Synostosis (plural: synostoses) is fusion of two bones. It can be normal in puberty, fusion of the epiphysis, or abnormal. When synostosis is abnormal it is a type of dysostosis.

Examples of synostoses include:

- craniosynostosis – an abnormal fusion of two or more cranial bones;

- radioulnar synostosis – the abnormal fusion of the radius and ulna bones of the forearm;

- tarsal coalition – a failure to separately form all seven bones of the tarsus (the hind part of the foot) resulting in an amalgamation of two bones; and

- syndactyly – the abnormal fusion of neighboring digits.

Synostosis within joints can cause ankylosis.

Radioulnar synostosis is one of the more common failures of separation of parts of the upper limb. There are two general types: one is characterized by fusion of the radius and ulna at their proximal borders and the other is fused distal to the proximal radial epiphysis. Most cases are sporadic, congenital (due to a defect in longitudinal segmentation at the 7th week of development) and less often post-traumatic, bilateral in 60%, and more common in males. Familial cases in association with autosomal dominant transmission appear to be concentrated in certain geographic regions, such as Sicily.

The condition frequently is not noted until late childhood, as function may be normal, especially in unilateral cases. Increased wrist motion may compensate for the absent forearm motion. It has been suggested that individuals whose forearms are fixed in greater amounts of pronation (over 60 degrees) face more problems with function than those with around 20 degrees of fixation. Pain is generally not a problem, unless radial head dislocation should occur.

Most examples of radioulnar synostosis are isolated (non-syndromic). Syndromes that may be accompanied by radioulnar synostosis include X chromosome polyploidy (e.g., XXXY) and other chromosome disorders (e.g., 4p- syndrome, Williams syndrome), acrofacial dysostosis, Antley–Bixler syndrome, genitopatellar syndrome, Greig cephalopolysyndactyly syndrome, hereditary multiple osteochondromas (hereditary multiple exostoses), limb-body wall complex, and Nievergelt syndrome.

Craniosynostosis (from cranio, cranium; + syn, together; + ostosis relating to bone) is a condition in which one or more of the fibrous sutures in an infant skull prematurely fuses by turning into bone (ossification). Craniosynostosis has following kinds: scaphocephaly, trigonocephaly, plagiocephaly, anterior plagiocephaly, posterior plagiocephaly, brachycephaly, oxycephaly, pansynostosis.

The diagnosis of constriction ring syndrome can be confirmed with an ultrasonography. The clinical manifestations can be extremely variable. It could be a single or multiple manifestation. This can be confirmed at the end of the first trimester or at the beginning of the second trimester. But not every patient will be diagnosed at that moment, most will get this diagnosis at birth.

The bones of children are very malleable in infancy. This will generally mean that, despite the presence of a coalition, the bones can deform enough to allow painless walking until the child's skeleton has matured enough. 'Skeletal maturing' means that bone is laid down in the tissue that forms the immature bone shape gradually until adult bone is achieved at about the age of seventeen years in the feet. Other body parts reach skeletal maturity at different times. The onset of symptoms related to a tarsal coalition usually occurs at about nine to seventeen years of age, with a peak incidence occurring at ten to fourteen years of age. Symptoms may start suddenly one day and persist, and can include pain (may be quite severe), lack of endurance for activity, fatigue, muscle spasms and cramps, an inability to rotate the foot, or antalgic gait.

The differential diagnosis includes;

- Symbrachydactyly

- Chorionic villus sampling

- Congenital amputations

- Hypoplasias of hand, digit, thumb

- Adams-Oliver syndrome

- ADAM complex

ADAM Complex; CRS is sometimes mislabeled as ADAM complex. ADAM is an abbreviation for Amniotic Deformity, Adhesions Mutilations. CRS is the malformation due to a constriction ring around mostly a limb. ADAM-complex is the association of limb defects (caused by constriction rings) and certain craniofacial clefts

“Adams-Oliver syndrome is often mislabeled as CRS and consists of cutis aplasia of the scalp in which a longitudinal defect can vary in size and can often be associated with full-thickness skullcap loss. The distal digital or toe hypoplasia-aplasia is often confused with CRS. Constriction rings with or without edema are not present. The digital or toe hypoplasia-aplasia usually contains diminutive nails or nail folds”.

Tarsal coalition (also known as peroneal spastic flatfoot, calcaneonavicular bar, talocalcaneal bar, tarsal synostosis, or tarsal dysostosis) is an abnormal connecting bridge of tissue between two normally-separate tarsal bones. The term 'coalition' means a coming together of two or more entities to merge into one mass. The tissue connecting the bones, often referred to as a "bar", may be composed of fibrous or osseous tissue. The two most common types of tarsal coalitions are calcaneo-navicular and talo-calcaneal, comprising 90% of all tarsal coalitions. There are other bone coalition combinations possible, but they are very rare. Symptoms tend to occur in the same location, regardless of the location of coalition: on the lateral foot, just anterior and below the lateral malleolus. This area is called the sinus tarsi.

Studies have shown children and adolescents with flat feet are a common occurrence. The human arch develops in infancy and early childhood as part of normal muscle, tendon, ligament and bone growth . Flat arches in children usually become high arches as the child progresses through adolescence and into adulthood. Since children are unlikely to suspect or identify flat feet on their own, it is important for adult caregivers to check on this themselves. Besides visual inspection, caregivers should notice when a child's gait is abnormal. Children who complain about calf muscle pains, arch pain, or any other pains around the foot area may be developing or have developed flat feet. Children with flat feet are at a higher risk of developing knee, hip, and back pain. A recent randomized controlled trial found no evidence for the efficacy of treatment of flat feet in children either from expensive prescribed orthotics i.e (shoe inserts) or less expensive over-the-counter orthotics. As a symptom itself, flat feet usually accompany genetic musculoskeletal conditions such as dyspraxia, ligamentous laxity or hypermobility.

Flat feet (also called pes planus or fallen arches) is a postural deformity in which the arches of the foot collapse, with the entire sole of the foot coming into complete or near-complete contact with the ground. Some individuals (an estimated 20–30% of the general population) have an arch that simply never develops in one foot (unilaterally) or both feet (bilaterally).

There is a functional relationship between the structure of the arch of the foot and the biomechanics of the lower leg. The arch provides an elastic, springy connection between the forefoot and the hind foot. This association safeguards so that a majority of the forces incurred during weight bearing of the foot can be dissipated before the force reaches the long bones of the leg and thigh.

In pes planus, the head of the talus bone is displaced medially and distal from the navicular. As a result, the Plantar calcaneonavicular ligament (spring ligament) and the tendon of the tibialis posterior muscle are stretched, so much so that the individual with pes planus loses the function of the medial longitudinal arch (MLA). If the MLA is absent or nonfunctional in both the seated and standing positions, the individual has “rigid” flatfoot. If the MLA is present and functional while the individual is sitting or standing up on their toes, but this arch disappears when assuming a foot-flat stance, the individual has “supple” flatfoot. This latter condition can be correctable with well-fitting arch supports.

Three studies (see citations below in military section) of military recruits have shown no evidence of later increased injury, or foot problems, due to flat feet, in a population of people who reach military service age without prior foot problems. However, these studies cannot be used to judge possible future damage from this condition when diagnosed at younger ages. They also cannot be applied to persons whose flat feet are associated with foot symptoms, or certain symptoms in other parts of the body (such as the leg or back) possibly referable to the foot.

Lisfranc injury, also known as Lisfranc fracture, is an injury of the foot in which one or more of the metatarsal bones are displaced from the tarsus. The injury is named after Jacques Lisfranc de St. Martin (2 April 179013 May 1847), a French surgeon and gynecologist who described an amputation of the foot through the tarsometatarsal articulation, in 1815, after the War of the Sixth Coalition.

In humans, the midfoot consists of five bones that form the arches of the foot (the cuboid, navicular, and three cuneiform bones) and their articulations with the bases of the five metatarsal bones. Lisfranc injuries are caused when excessive kinetic energy is applied either directly or indirectly to the midfoot and are often seen in traffic collisions or industrial accidents.

Direct Lisfranc injuries are usually caused by a crush injury, such as a heavy object falling onto the midfoot, or the foot being run over by a car or truck, or someone landing on the foot after a fall from a significant height. Indirect Lisfranc injuries are caused by a sudden rotational force on a plantar flexed (downward pointing) forefoot. Examples of this type of trauma include a rider falling from a horse but the foot remaining trapped in the stirrup, or a person falling forward after stepping into a storm drain.

In athletic trauma, Lisfranc injuries occur commonly in activities such as windsurfing, kitesurfing, wakeboarding, or snowboarding (where appliance bindings pass directly over the metatarsals). American football players occasionally acquire this injury, and it most often occurs when the athlete's foot is plantar flexed and another player lands on the heel. This can also be seen in pivoting athletic positions such as a baseball catcher or a ballerina spinning.

Blast-related ocular trauma comprises a specialized group of penetrating and blunt force injuries to the eye and its structure caused by the detonation of explosive materials. The incidence of ocular trauma due to blast forces has increased dramatically with the introduction of new explosives technology into modern warfare. The availability of these volatile materials, coupled with the tactics of contemporary terrorism, has caused a rise in the number of homemade bombs capable of extreme physical harm.

About 96% of individuals with aortic dissection present with severe pain that had a sudden onset. The pain may be described as a tearing, stabbing, or sharp sensation; 17% of individuals feel the pain migrate as the dissection extends down the aorta. The location of pain is associated with the location of the dissection. Anterior chest pain is associated with dissections involving the ascending aorta, while interscapular (back) pain is associated with descending aortic dissections. If the pain is pleuritic in nature, it may suggest acute pericarditis caused by bleeding into the pericardial sac. This is a particularly dangerous eventuality, suggesting that acute pericardial tamponade may be imminent. Pericardial tamponade is the most common cause of death from aortic dissection.

While the pain may be confused with the pain of a myocardial infarction (heart attack), aortic dissection is usually not associated with the other signs that suggest myocardial infarction, including heart failure and ECG changes.

Individuals with aortic dissection who do not present with pain have a chronic dissection.

Less common symptoms that may be seen in the setting of aortic dissection include congestive heart failure (7%), fainting (9%), stroke (6%), ischemic peripheral neuropathy, paraplegia, and cardiac arrest. If the individual had a fainting episode, about half the time it is due to bleeding into the pericardium leading to pericardial tamponade.

Neurological complications of aortic dissection (i.e., stroke and paralysis) are due to the involvement of one or more arteries supplying portions of the central nervous system.

If the aortic dissection involves the abdominal aorta, compromise of the branches of the abdominal aorta is possible. In abdominal aortic dissections, compromise of one or both renal arteries occurs in 5–8% of cases, while mesenteric ischemia (ischemia of the large intestines) occurs 3–5% of the time.

People with an aortic dissection often have a history of high blood pressure; the blood pressure is quite variable at presentation with acute aortic dissection, and tends to be higher in individuals with a distal dissection. In individuals with a proximal aortic dissection, 36% present with hypertension, while 25% present with hypotension. Proximal aortic dissections tend to be more associated with weakening of the vascular wall due to cystic medial degeneration. In those who present with distal (type B) aortic dissections, 60-70% present with high blood pressure, while 2-3% present with low blood pressure.

Severe hypotension at presentation is a grave prognostic indicator. It is usually associated with pericardial tamponade, severe aortic insufficiency, or rupture of the aorta. Accurate measurement of the blood pressure is important. Pseudohypotension (falsely low blood-pressure measurement) may occur due to involvement of the brachiocephalic artery (supplying the right arm) or the left subclavian artery (supplying the left arm).

The majority of blast-related ocular injuries occur in soldiers who present with other life-threatening injuries that require immediate intervention. Current Combat Support Hospital (CSH) protocol requires the surgical stabilization of any life-threatening injuries, as well as hemodynamic stability, prior to initial eye evaluation and surgical repair. Therefore, initiation of emergency ophthalmic care often occurs hours after injury. Initial examination by a military ophthalmologist begins with gross examination of each eye and orbital. 73-82% of all ocular injuries resulting from mine explosions are due to fragmentation of shrapnel upon detonation, so gross anatomical inspection by penlight may not rule out open globe injury. Harlan JB, Pieramici DJ. Evaluation of patients with ocular trauma. Ophthalmol Clin North Am. 2002; 15(2):153-61./ref> Computerized tomography (CT) may detect foreign matter and aid the clinician in determining the presence of an open-globe injury.

The first noticeable symptom of breast cancer is typically a lump that feels different from the rest of the breast tissue. More than 80% of breast cancer cases are discovered when the woman feels a lump. The earliest breast cancers are detected by a mammogram. Lumps found in lymph nodes located in the armpits can also indicate breast cancer.

Indications of breast cancer other than a lump may include thickening different from the other breast tissue, one breast becoming larger or lower, a nipple changing position or shape or becoming inverted, skin puckering or dimpling, a rash on or around a nipple, discharge from nipple/s, constant pain in part of the breast or armpit, and swelling beneath the armpit or around the collarbone. Pain ("mastodynia") is an unreliable tool in determining the presence or absence of breast cancer, but may be indicative of other breast health issues.

Inflammatory breast cancer is a particular type of breast cancer which can pose a substantial diagnostic challenge. Symptoms may resemble a breast inflammation and may include itching, pain, swelling, nipple inversion, warmth and redness throughout the breast, as well as an orange-peel texture to the skin referred to as "peau d'orange". As inflammatory breast cancer does not present as a lump there can sometimes be a delay in diagnosis.

Another reported symptom complex of breast cancer is Paget's disease of the breast. This syndrome presents as skin changes resembling eczema, such as redness, discoloration, or mild flaking of the nipple skin. As Paget's disease of the breast advances, symptoms may include tingling, itching, increased sensitivity, burning, and pain. There may also be discharge from the nipple. Approximately half of women diagnosed with Paget's disease of the breast also have a lump in the breast.

In rare cases, what initially appears as a fibroadenoma (hard, movable non-cancerous lump) could in fact be a phyllodes tumor. Phyllodes tumors are formed within the stroma (connective tissue) of the breast and contain glandular as well as stromal tissue. Phyllodes tumors are not staged in the usual sense; they are classified on the basis of their appearance under the microscope as benign, borderline, or malignant.

Occasionally, breast cancer presents as metastatic disease—that is, cancer that has spread beyond the original organ. The symptoms caused by metastatic breast cancer will depend on the location of metastasis. Common sites of metastasis include bone, liver, lung and brain. Unexplained weight loss can occasionally signal breast cancer, as can symptoms of fevers or chills. Bone or joint pains can sometimes be manifestations of metastatic breast cancer, as can jaundice or neurological symptoms. These symptoms are called "non-specific", meaning they could be manifestations of many other illnesses.

Most symptoms of breast disorders, including most lumps, do not turn out to represent underlying breast cancer. Fewer than 20% of lumps, for example, are cancerous, and benign breast diseases such as mastitis and fibroadenoma of the breast are more common causes of breast disorder symptoms. Nevertheless, the appearance of a new symptom should be taken seriously by both patients and their doctors, because of the possibility of an underlying breast cancer at almost any age.

The severity of COVID-19 varies. The disease may take a mild course with few or no symptoms, resembling other common upper respiratory diseases such as the common cold. Mild cases typically recover within two weeks, while those with severe or critical diseases may take three to six weeks to recover. Among those who have died, the time from symptom onset to death has ranged from two to eight weeks.

Children are susceptible to the disease, but are likely to have milder symptoms and a lower chance of severe disease than adults; in those younger than 50 years, the risk of death is less than 0.5%, while in those older than 70 it is more than 8%. Pregnant women may be at higher risk for severe infection with COVID-19 based on data from other similar viruses, like SARS and MERS, but data for COVID-19 is lacking.

In some people, COVID-19 may affect the lungs causing pneumonia. In those most severely affected, COVID-19 may rapidly progress to acute respiratory distress syndrome (ARDS) causing respiratory failure, septic shock or multi-organ failure. Complications associated with COVID-19 include sepsis, abnormal clotting and damage to the heart, kidneys and liver. Clotting abnormalities, specifically an increase in prothrombin time, have been described in 6% of those admitted to hospital with COVID-19, while abnormal kidney function is seen in 4% of this group. Approximately 20-30% of people who present with COVID-19 demonstrate elevated liver enzymes (transaminases). Liver injury as shown by blood markers of liver damage is frequently seen in severe cases.

Some studies have found that the neutrophil to lymphocyte ratio (NLR) may be helpful in early screening for severe illness.

Many of those who die of COVID-19 have pre-existing (underlying) conditions, including hypertension, diabetes mellitus and cardiovascular disease. The Istituto Superiore di Sanità reported that out of 8.8% of deaths where medical charts were available for review, 97.2% of sampled patients had at least one comorbidity with the average patient having 2.7 diseases. According to the same report, the median time between onset of symptoms and death was ten days, with five being spent hospitalised. However, patients transferred to an ICU had a median time of seven days between hospitalisation and death. In a study of early cases, the median time from exhibiting initial symptoms to death was 14 days, with a full range of six to 41 days. In a study by the National Health Commission (NHC) of China, men had a death rate of 2.8% while women had a death rate of 1.7%. Histopathological examinations of post-mortem lung samples show diffuse alveolar damage with cellular fibromyxoid exudates in both lungs. Viral cytopathic changes were observed in the pneumocytes. The lung picture resembled acute respiratory distress syndrome (ARDS). In 11.8% of the deaths reported by the National Health Commission of China, heart damage was noted by elevated levels of troponin or cardiac arrest. According to March data from the United States, 89% of those hospitalised had preexisting conditions.

Availability of medical resources and the socioeconomics of a region may also affect mortality. Estimates of the mortality from the condition vary because of those regional differences, but also because of methodological difficulties. The under-counting of mild cases can cause the mortality rate to be overestimated. However, the fact that deaths are the result of cases contracted in the past can mean the current mortality rate is underestimated. Smokers were 1.4 times more likely to have severe symptoms of COVID-19 and approximately 2.4 times more likely to require intensive care or die compared to non-smokers.

Concerns have been raised about long-term sequelae of the disease. The Hong Kong Hospital Authority found a drop of 20% to 30% in lung capacity in some people who recovered from the disease, and lung scans suggested organ damage. This may also lead to post-intensive care syndrome following recovery.

Total infection fatality rate is estimated to be 0.66% (0.39–1.3). Infection fatality rate is fatality per all infected individuals, regardless of whether they were diagnosed or had any symptoms. Numbers in parentheses are 95% credible intervals for the estimates.

Gulf War syndrome (GWS), also known as Gulf War illnesses (GWI) and chronic multisymptom illness (CMI), is a chronic and multisymptomatic disorder affecting returning military veterans and civilian workers of the 1990–91 Gulf War. A wide range of acute and chronic symptoms have been linked to it, including fatigue, muscle pain, cognitive problems, rashes and diarrhea. Approximately 250,000 of the 697,000 U.S. veterans who served in the 1991 Gulf War are afflicted with enduring chronic multi-symptom illness, a condition with serious consequences. From 1995 to 2005, the health of combat veterans worsened in comparison with nondeployed veterans, with the onset of more new chronic diseases, functional impairment, repeated clinic visits and hospitalizations, chronic fatigue syndrome-like illness, posttraumatic stress disorder, and greater persistence of adverse health incidents. According to a report by the Iraq and Afghanistan Veterans of America, veterans of Iraq and Afghanistan may also suffer from the syndrome.

Suggested causes have included depleted uranium, sarin gas, smoke from burning oil wells, vaccinations, combat stress and psychological factors.

The U.S. Department of Veterans Affairs (VA) describes Gulf War syndrome as "Gulf War veterans' medically unexplained illnesses" and refers to it as chronic multisymptom illness (CMI) and undiagnosed illnesses. The VA also explains that it doesn't use the term "Gulf War syndrome" when referring to medically unexplained symptoms reported by Gulf War veterans because the symptoms vary widely.

Early prostate cancer usually has no clear symptoms. Sometimes, however, prostate cancer does cause symptoms, often similar to those of diseases such as benign prostatic hyperplasia. These include frequent urination, nocturia (increased urination at night), difficulty starting and maintaining a steady stream of urine, hematuria (blood in the urine), and dysuria (painful urination). A study based on the 1998 Patient Care Evaluation in the US found that about a third of patients diagnosed with prostate cancer had one or more such symptoms, while two-thirds had no symptoms.

Prostate cancer is associated with urinary dysfunction as the prostate gland surrounds the prostatic urethra. Changes within the gland, therefore, directly affect urinary function. Because the "vas deferens" deposits seminal fluid into the prostatic urethra, and secretions from the prostate gland itself are included in semen content, prostate cancer may also cause problems with sexual function and performance, such as difficulty achieving erection or painful ejaculation.

Metastatic prostate cancer that has spread to other parts of the body can cause additional symptoms. The most common symptom is bone pain, often in the vertebrae (bones of the spine), pelvis, or ribs. Spread of cancer into other bones such as the femur is usually to the proximal or nearby part of the bone. Prostate cancer in the spine can also compress the spinal cord, causing tingling, leg weakness and urinary and fecal incontinence.

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The disease was first identified in December 2019 in Wuhan, the capital of China's Hubei province, and has since spread globally, resulting in the ongoing 2019–20 coronavirus pandemic. Common symptoms include fever, cough, and shortness of breath. Other symptoms may include fatigue, muscle pain, diarrhea, sore throat, loss of smell, and abdominal pain. The time from exposure to onset of symptoms is typically around five days but may range from two to fourteen days. While the majority of cases result in mild symptoms, some progress to viral pneumonia and multi-organ failure. As of 17 April 2020, more than 2.23 million cases have been reported across 210 countries and territories, resulting in more than 153,000 deaths. More than 567,000 people have recovered.

The virus is primarily spread between people during close contact, often via small droplets produced by coughing, sneezing, or talking. While these droplets are produced when breathing out, they usually fall to the ground or onto surfaces rather than being infectious over long distances. People may also become infected by touching a contaminated surface and then touching their eyes, nose, or mouth. The virus can survive on surfaces up to 72 hours. It is most contagious during the first three days after the onset of symptoms, although spread may be possible before symptoms appear and in later stages of the disease.

The standard method of diagnosis is by real-time reverse transcription polymerase chain reaction (rRT-PCR) from a nasopharyngeal swab. Chest CT imaging may also be helpful for diagnosis in individuals where there is a high suspicion of infection based on symptoms and risk factors; however, it is not recommended for routine screening.

Recommended measures to prevent infection include frequent hand washing, maintaining physical distance from others (especially from those with symptoms), covering coughs and sneezes with a tissue or inner elbow, and keeping unwashed hands away from the face. The use of masks is recommended for those who suspect they have the virus and their caregivers. Recommendations for mask use by the general public vary, with some authorities recommending against their use, some recommending their use, and others requiring their use. Currently, there is no vaccine or specific antiviral treatment for COVID-19. Management involves treatment of symptoms, supportive care, isolation, and experimental measures.

The World Health Organization (WHO) declared the 2019–20 coronavirus outbreak a Public Health Emergency of International Concern (PHEIC) on 30 January 2020 and a pandemic on 11 March 2020. Local transmission of the disease has been recorded in most countries across all six WHO regions.

A needlestick injury, percutaneous injury, or percutaneous exposure incident is the penetration of skin by a needle or other sharp object, which was in contact with blood, tissue, or other body fluid before the exposure. Occupational needlestick injuries primarily affect healthcare workers, who make up 80% of needlestick injuries in the United States. Various other occupations are also at increased risk of needlestick injury, including law enforcement, laborers, tattoo artists, food preparers, and agricultural workers. Though the acute physiological effects of a needlestick injury are generally negligible, these devices can transmit blood-borne diseases, placing those exposed at increased risk of contracting infectious diseases, such as hepatitis B (HBV), hepatitis C (HCV), and the human immunodeficiency virus (HIV). Among healthcare workers and laboratory personnel worldwide, more than 25 blood-borne viruses have been reported to be caused by needlestick injuries.

It is estimated that half of all occupational needlestick injuries are not reported. Additionally, an unknown number of occupational needlestick injuries are reported by the affected employee, yet due to organizational failure, institutional record of the injury does not exist. Increasing recognition of the unique occupational hazard posed by needlestick injuries, as well as the development of efficacious interventions to minimize the largely preventable occupational risk, encouraged legislative regulation in the US, causing a decline in needlestick injuries among healthcare workers.

Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, fluid coming from the nipple, or a red scaly patch of skin. In those with distant spread of the disease, there may be bone pain, swollen lymph nodes, shortness of breath, or yellow skin.

Risk factors for developing breast cancer include being female, obesity, lack of physical exercise, drinking alcohol, hormone replacement therapy during menopause, ionizing radiation, early age at first menstruation, having children late or not at all, older age, and family history. About 5–10% of cases are due to genes inherited from a person's parents, including BRCA1 and BRCA2 among others. Breast cancer most commonly develops in cells from the lining of milk ducts and the lobules that supply the ducts with milk. Cancers developing from the ducts are known as ductal carcinomas, while those developing from lobules are known as lobular carcinomas. In addition, there are more than 18 other sub-types of breast cancer. Some cancers, such as ductal carcinoma in situ, develop from pre-invasive lesions. The diagnosis of breast cancer is confirmed by taking a biopsy of the concerning lump. Once the diagnosis is made, further tests are done to determine if the cancer has spread beyond the breast and which treatments it may respond to.

The balance of benefits versus harms of breast cancer screening is controversial. A 2013 Cochrane review stated that it is unclear if mammographic screening does more good or harm. A 2009 review for the US Preventive Services Task Force found evidence of benefit in those 40 to 70 years of age, and the organization recommends screening every two years in women 50 to 74 years old. The medications tamoxifen or raloxifene may be used in an effort to prevent breast cancer in those who are at high risk of developing it. Surgical removal of both breasts is another preventative measure in some high risk women. In those who have been diagnosed with cancer, a number of treatments may be used, including surgery, radiation therapy, chemotherapy, hormonal therapy and targeted therapy. Types of surgery vary from breast-conserving surgery to mastectomy. Breast reconstruction may take place at the time of surgery or at a later date. In those in whom the cancer has spread to other parts of the body, treatments are mostly aimed at improving quality of life and comfort.

Outcomes for breast cancer vary depending on the cancer type, extent of disease, and person's age. Survival rates in the developed world are high, with between 80% and 90% of those in England and the United States alive for at least 5 years. In developing countries survival rates are poorer. Worldwide, breast cancer is the leading type of cancer in women, accounting for 25% of all cases. In 2012 it resulted in 1.68 million new cases and 522,000 deaths. It is more common in developed countries and is more than 100 times more common in women than in men.

Prostate cancer is the development of cancer in the prostate, a gland in the male reproductive system. Most prostate cancers are slow growing; however, some grow relatively quickly. The cancer cells may spread from the prostate to other parts of the body, particularly the bones and lymph nodes. It may initially cause no symptoms. In later stages it can lead to difficulty urinating, blood in the urine, or pain in the pelvis, back or when urinating. A disease known as benign prostatic hyperplasia may produce similar symptoms. Other late symptoms may include feeling tired due to low levels of red blood cells.

Factors that increase the risk of prostate cancer include: older age, a family history of the disease, and race. About 99% of cases occur in those over the age of 50. Having a first-degree relative with the disease increases the risk two to threefold. In the United States, it is more common in the African American population than the white American population. Other factors that may be involved include a diet high in processed meat, red meat, or milk products or low in certain vegetables. An association with gonorrhea has been found, but a reason for this relationship has not been identified. Prostate cancer is diagnosed by biopsy. Medical imaging may then be done to determine if the cancer has spread to other parts of the body.

Prostate cancer screening is controversial. Prostate-specific antigen (PSA) testing increases cancer detection but does not decrease mortality. The United States Preventive Services Task Force recommends against screening using the PSA test, due to the risk of overdiagnosis and overtreatment, as most cancer diagnosed would remain asymptomatic. The USPSTF concludes that the potential benefits of testing do not outweigh the expected harms. While 5α-reductase inhibitors appear to decrease low-grade cancer risk they do not affect high-grade cancer risk and thus are not recommended for prevention. Supplementation with vitamins or minerals does not appear to affect the risk.

Many cases can be safely followed with active surveillance or watchful waiting. Other treatments may include a combination of surgery, radiation therapy, hormone therapy or chemotherapy. When it only occurs inside the prostate it may be curable. In those in whom the disease has spread to the bones, pain medications, bisphosphonates and targeted therapy, among others, may be useful. Outcomes depend on a person's age and other health problems as well as how aggressive and extensive the cancer is. Most people with prostate cancer do not end up dying from the disease. The 5-year survival rate in the United States is 99%. Globally it is the second most common type of cancer and the fifth leading cause of cancer-related death in men. In 2012 it occurred in 1.1 million men and caused 307,000 deaths. It was the most common cancer in males in 84 countries, occurring more commonly in the developed world. Rates have been increasing in the developing world. Detection increased significantly in the 1980s and 1990s in many areas due to increased PSA testing. Studies of males who died from unrelated causes have found prostate cancer in 30% to 70% of those over age 60.

Medical ailments associated with Gulf War syndrome have been recognized by both the Department of Defense and the Department of Veterans Affairs. Since so little concrete information was known about this condition the Veterans Health Administration (VHA) originally classified individuals with related ailments believed to be connected to their service in the Persian Gulf a special non-ICD-9 code DX111, as well as ICD-9 code V65.5. There is no formal definition of the term "Gulf War syndrome" or "Gulf War illnesses".

The bacterium has an incubation period of 5 to 12 days, after which the affected individual experiences symptoms of conjunctivitis, or irritation similar to "pink eye." Blinding endemic trachoma results from multiple episodes of reinfection that maintains the intense inflammation in the conjunctiva. Without reinfection, the inflammation will gradually subside.

The conjunctival inflammation is called “active trachoma” and usually is seen in children, especially pre-school children. It is characterized by white lumps in the undersurface of the upper eyelid (conjunctival follicles or lymphoid germinal centres) and by non-specific inflammation and thickening often associated with papillae. Follicles may also appear at the junction of the cornea and the sclera (limbal follicles). Active trachoma will often be irritating and have a watery discharge. Bacterial secondary infection may occur and cause a purulent discharge.

The later structural changes of trachoma are referred to as “cicatricial trachoma”. These include scarring in the eyelid (tarsal conjunctiva) that leads to distortion of the eyelid with buckling of the lid (tarsus) so the lashes rub on the eye (trichiasis). These lashes will lead to corneal opacities and scarring and then to blindness. Linear scar present in the Sulcus subtarsalis is called Arlt's line (named after Carl Ferdinand von Arlt). In addition, blood vessels and scar tissue can invade the upper cornea (pannus). Resolved limbal follicles may leave small gaps in pannus (Herbert’s Pits).

Most commonly children with active trachoma will not present with any symptoms as the low-grade irritation and ocular discharge is just accepted as normal. However, further symptoms may include:

- Eye discharge

- Swollen eyelids

- Trichiasis (turned-in eyelashes)

- Swelling of lymph nodes in front of the ears

- Sensitivity to bright lights

- Increased heart rate

- Further ear, nose and throat complications.

The major complication or the most important one is corneal ulcer occurring due to rubbing by concentrations, or trichiasis with superimposed bacterial infection.

Alcoholic beverages are classified by the International Agency for Research on Cancer (IARC) as a Group 1 carcinogen (carcinogenic to humans). IARC classifies alcoholic beverage consumption as a cause of female breast, colorectum, larynx, liver, esophagus, oral cavity, and pharynx cancers; and as a probable cause of pancreatic cancer.

3.6% of all cancer cases and 3.5% of cancer deaths worldwide are attributable to consumption of alcohol (also known formally as ethanol).