German entomologist Fritz Zumpt describes myiasis as "the infestation of live human and vertebrate animals with dipterous larvae, which at least for a period, feed on the host's dead or living tissue, liquid body substances, or ingested food". For modern purposes however, this is too vague. For example, feeding on dead or necrotic tissue is not generally a problem except when larvae such as those of flies in the family Piophilidae attack stored food such as cheese or preserved meats; such activity suggests saprophagy rather than parasitism; it even may be medically beneficial in maggot debridement therapy (MDT).

Currently myiasis commonly is classified according to aspects relevant to the case in question:

- The classical description of myiasis is according to the part of the host that is infected. This is the classification used by ICD-10. For example:

- dermal

- sub-dermal

- cutaneous (B87.0)

- creeping, where larvae burrow through or under the skin

- furuncular, where a larva remains in one spot, causing a boil-like lesion

- nasopharyngeal, in the nose, sinuses or pharynx (B87.3)

- ophthalmic or ocular, in or about the eye (B87.2)

- auricular, in or about the ear

- gastric, rectal, or intestinal/enteric for the appropriate part of the digestive system (B87.8)

- urogenital (B87.8)

- Another aspect is the relationship between the host and the parasite and provides insight into the biology of the fly species causing the myiasis and its likely effect. Thus the myiasis is described as either:

- obligatory, where the parasite cannot complete its life cycle without its parasitic phase, which may be specific, semispecific, or opportunistic

- facultative, incidental, or accidental, where it is not essential to the life cycle of the parasite; perhaps a normally free-living larva accidentally gained entrance to the host

Accidental myiasis commonly is enteric, resulting from swallowing eggs or larvae with one's food. The effect is called "pseudomyiasis". One traditional cause of pseudomyiasis was the eating of maggots of cheese flies in cheeses such as Stilton. Depending on the species present in the gut, pseudomyiasis may cause significant medical symptoms, but it is likely that most cases pass unnoticed.

The first control method is preventive and aims to eradicate the adult flies before they can cause any damage and is called vector control. The second control method is the treatment once the infestation is present, and concerns the infected animals (including humans).

The principal control method of adult populations of myiasis inducing flies involves insecticide applications in the environment where the target livestock is kept. Organophosphorus or organochlorine compounds may be used, usually in a spraying formulation. One alternative prevention method is the sterile insect technique (SIT) where a significant number of artificially reared sterilized (usually through irradiation) male flies are introduced. The male flies compete with wild breed males for females in order to copulate and thus cause females to lay batches of unfertilized eggs which cannot develop into the larval stage.

One prevention method involves removing the environment most favourable to the flies, such as by removal of the tail. Another example is the crutching of sheep, which involves the removal of wool from around the tail and between the rear legs, which is a favourable environment for the larvae. Another, more permanent, practice which is used in some countries is mulesing, where skin is removed from young animals to tighten remaining skin – leaving it less prone to fly attack.

To prevent myiasis in humans, there is a need for general improvement of sanitation, personal hygiene, and extermination of the flies by insecticides. Clothes should be washed thoroughly, preferably in hot water, dried away from flies, and ironed thoroughly. The heat of the iron kills the eggs of myiasis-causing flies.

There are several preventative measures which are used to reduce the occurrence of flystrike in sheep flocks, these include:

- Controlling intestinal parasites to prevent scours and a suitable surface for flystrike

- Scheduled shearing and crutching

- Removing the tails of lambs at weaning

- Mulesing

- Preventative chemical treatments before fly infestation risk is high

- Breeding for traits that reduce the likelihood of infestation

- Removing or avoiding large maunure heaps or other sites attractive to the flies

- Using fly traps near the flock to attract and kill any local flies, helping to minimise the local populations. NB: Traps often emit a pungent smell and are best placed away from human activity.

None of these measures completely stop the occurrence of fly strike in sheep, and regular treatment is still necessary.

If infested, animals should be removed from the flock and all wool in and around roughly a 1 cm or larger radius of the discoloured area clipped. The area is treated with insecticide to kill the maggots. Soothing cream can also be applied to skin grazes or lesions caused by the maggots. Clippings should be collected after removal and placed in a maggot-proof bag and left closed in the sun, to ensure that no other animal is infected.

Identification of the snake is important in planning treatment in certain areas of the world, but is not always possible. Ideally the dead snake would be brought in with the person, but in areas where snake bite is more common, local knowledge may be sufficient to recognize the snake. However, in regions where polyvalent antivenoms are available, such as North America, identification of snake is not a high priority item. Attempting to catch or kill the offending snake also puts one at risk for re-envenomation or creating a second person bitten, and generally is not recommended.

The three types of venomous snakes that cause the majority of major clinical problems are vipers, kraits, and cobras. Knowledge of what species are present locally can be crucial, as is knowledge of typical signs and symptoms of envenomation by each type of snake. A scoring system can be used to try to determine the biting snake based on clinical features, but these scoring systems are extremely specific to particular geographical areas.

It is not an easy task determining whether or not a bite by any species of snake is life-threatening. A bite by a North American copperhead on the ankle is usually a moderate injury to a healthy adult, but a bite to a child's abdomen or face by the same snake may be fatal. The outcome of all snakebites depends on a multitude of factors: the size, physical condition, and temperature of the snake, the age and physical condition of the person, the area and tissue bitten (e.g., foot, torso, vein or muscle), the amount of venom injected, the time it takes for the person to find treatment, and finally the quality of that treatment.

To determine the need for referral to a specialized burn unit, the American Burn Association devised a classification system. Under this system, burns can be classified as major, moderate and minor. This is assessed based on a number of factors, including total body surface area affected, the involvement of specific anatomical zones, the age of the person, and associated injuries. Minor burns can typically be managed at home, moderate burns are often managed in hospital, and major burns are managed by a burn center.

One recommended method of removal is using a fingernail or other flat, blunt object to break the seal of the oral sucker at the anterior end of the leech, repeating with the posterior end, then flicking the leech away. As the fingernail is pushed along the person's skin against the leech, the suction of the sucker's seal is broken, at which point the leech will detach its jaws.

Common, but medically inadvisable, techniques to remove a leech are to apply a flame, a lit cigarette, salt, soap, or a chemical such as alcohol, vinegar, lemon juice, insect repellent, heat rub, or certain carbonated drinks. These will cause the leech to quickly detach; however, it will also regurgitate its stomach contents into the wound. The vomit may carry disease, and thus increase the risk of infection.

An externally attached leech will detach and fall off on its own when it is satiated on blood, which may be anywhere from 20 minutes to two hours or more. After feeding, the leech will detach and depart. Internal attachments, such as inside the nasal passage or vaginal attachments, are more likely to require medical intervention.

After removal or detachment, the wound should be cleaned with soap and water, and bandaged. Bleeding may continue for some time, due to the leech's hirudin. Bleeding time will vary, with location, from a few hours to three days. This is a function of the hirudin and other compounds that reduce the surface tension of the blood. Anticlotting medications also affect the bleeding time. Applying pressure can reduce bleeding, although blood loss from a single bite is not dangerous. The wound normally itches as it heals, but should not be scratched, as this may complicate healing and introduce other infections. An antihistamine can reduce itching, and applying a cold pack can reduce pain or swelling.

Some people have severe allergic or anaphylactic reactions from leech bites and require urgent medical care. Symptoms include red blotches or an itchy rash over the body, swelling around the lips or eyes, feeling faint or dizzy, and difficulty breathing.

The size of a burn is measured as a percentage of total body surface area (TBSA) affected by partial thickness or full thickness burns. First-degree burns that are only red in color and are not blistering are not included in this estimation. Most burns (70%) involve less than 10% of the TBSA.

There are a number of methods to determine the TBSA, including the Wallace rule of nines, Lund and Browder chart, and estimations based on a person's palm size. The rule of nines is easy to remember but only accurate in people over 16 years of age. More accurate estimates can be made using Lund and Browder charts, which take into account the different proportions of body parts in adults and children. The size of a person's handprint (including the palm and fingers) is approximately 1% of their TBSA.

Leeches are segmented worms that belong to the phylum Annelida and comprise the subclass Hirudinea. Like the oligochaetes, such as earthworms, leeches share a clitellum and are hermaphrodites. Nevertheless, they differ from the oligochaetes in significant ways. For example, leeches do not have bristles and the external segmentation of their bodies does not correspond with the internal segmentation of their organs. Their bodies are much more solid as the spaces in their coelom are dense with connective tissues. They also have two suckers, one at each end.

The majority of leeches live in freshwater environments, while some species can be found in terrestrial and marine environments. The best-known leeches, such as the medicinal leech, "Hirudo medicinalis", are hematophagous, feeding on vertebrate blood and invertebrate hemolymph. Most leech species, however, are predatory, feeding primarily by swallowing other invertebrates.

Almost 700 species of leeches are currently recognized, of which some 100 are marine, 90 terrestrial and the remainder freshwater taxa.

Leeches, such as the "Hirudo medicinalis", have been historically used in medicine to remove blood from patients. The practice of leeching can be traced to ancient India and Greece, and continued well into the 18th and 19th centuries in both Europe and North America. In modern times, leeches are used medically in procedures such as the reattachment of body parts and reconstructive and plastic surgeries and, in Germany, treating osteoarthritis.

A related condition, bisphosphonate-associated osteonecrosis of the jaw (BON), has been described as a side-effect of amino-bisphosphonates, a class of phosphorus-based drugs that inhibit bone resorption and are used widely for treating osteoporosis, bone disease in cancer and some other conditions.

BON, sometimes called "bis-phossy jaw",

is primarily associated with the use of intravenous bisphosphonates in the treatment of cancer. The percentage incidence of BON from this use is approximately 1000 times higher than the incidence of BON caused by the use of oral bisphosphonates.

Another human health issue caused by animal hoarding is the risk of zoonotic diseases. Defined as "human diseases acquired from or transmitted to any other vertebrate animal", zoonotic diseases can often be lethal and in all cases constitute a serious public health concern. Examples of well-known zoonotic diseases include bubonic plague, influenza, and rabies. Common domesticated animals constitute a large portion of animals carrying zoonoses, and as a result, humans involved in animal hoarding situations are at particular risk of contracting disease. Zoonoses that may arise in hoarding situations—through vectors such as dog, cat, or rat bites—include rabies, salmonellosis, catscratch fever, hookworm, and ringworm. One zoonosis of special concern is toxoplasmosis, which can be transmitted to humans through cat feces or badly-prepared meat, and is known to cause severe birth defects or stillbirth in the case of infected pregnant women. The risk of zoonotic diseases is amplified by the possibility of community epidemics.

Phossy jaw, formally phosphorus necrosis of the jaw, is an occupational disease of those who work with white phosphorus, also known as "yellow phosphorus", without proper safeguards. It was most commonly seen in workers in the match-stick industry in the 19th and early 20th century. Modern occupational hygiene practices have eliminated the working conditions which caused this disease. This disease is caused by the vapour of white phosphorus, which destroys the bones of the jaw.

As is common with specific phobias, an occasional fright may give rise to abnormal anxiety that requires treatment. An abnormal fear of bats may be treated by any standard treatment for specific phobias. Due to the fact that the fear is not life altering, it can usually just be left untreated.

As always, laboratory values have to be interpreted with the lab's reference values in mind and considering all aspects of the individual clinical situation.

Serum ferritin can be elevated in inflammatory conditions; so a normal serum ferritin may not always exclude iron deficiency, and the utility is improved by taking a concurrent C-reactive protein (CRP). The level of serum ferritin that is viewed as "high" depends on the condition. For example, in inflammatory bowel disease the threshold is 100, where as in chronic heart failure (CHF) the levels are 200.

The U.S. Preventive Services Task Force (USPSTF) issues recommendations for various cancers:

- Strongly recommends cervical cancer screening in women who are sexually active and have a cervix at least until the age of 65.

- Recommend that Americans be screened for colorectal cancer via fecal occult blood testing, sigmoidoscopy, or colonoscopy starting at age 50 until age 75.

- Evidence is insufficient to recommend for or against screening for skin cancer, oral cancer, lung cancer, or prostate cancer in men under 75.

- Routine screening is not recommended for bladder cancer, testicular cancer, ovarian cancer, pancreatic cancer, or prostate cancer.

- Recommends mammography for breast cancer screening every two years from ages 50–74, but does not recommend either breast self-examination or clinical breast examination. A 2013 Cochrane review concluded that breast cancer screening by mammography had no effect in reducing mortality because of overdiagnosis and overtreatment.

Contrary to a widespread misconception, only 3 species of bats feed on blood, and these species only live in Latin America. Common ignorance often leads to misidentification.

At the same time, the fear of bats may be naturally reinforced by the natural startle response experienced by an unsuspecting person, e.g., when a disturbed colony of bats dashes out of a cave. In fact, the majority of bats, specifically the microbats which make up the majority of species, are terrified of humans and see man as a potential predator; bats disturbed in their roost instinctively flee as fast as they can, with maternity colonies sometimes abandoning their babies since they are desperate to escape.

Often, people fear bats due to the possibility of contracting rabies, but only 0.5% of vampire bats carry rabies.

Screens for gastric cancer using photofluorography due to the high incidence there.

Initial diagnosis often is made during routine physical examination. Such diagnosis can be confirmed by a medical professional such as a neurologist, orthopedic surgeon or neurosurgeon. A person with foot drop will have difficulty walking on his or her heels because he will be unable to lift the front of the foot (balls and toes) off the ground. Therefore, a simple test of asking the patient to dorsiflex may determine diagnosis of the problem. This is measured on a 0-5 scale that observes mobility. The lowest point, 0, will determine complete paralysis and the highest point, 5, will determine complete mobility.

There are other tests that may help determine the underlying etiology for this diagnosis. Such tests may include MRI, MRN, or EMG to assess the surrounding areas of damaged nerves and the damaged nerves themselves, respectively. The nerve that communicates to the muscles that lift the foot is the peroneal nerve. This nerve innervates the anterior muscles of the leg that are used during dorsi flexion of the ankle. The muscles that are used in plantar flexion are innervated by the tibial nerve and often develop tightness in the presence of foot drop. The muscles that keep the ankle from supination (as from an ankle sprain) are also innervated by the peroneal nerve, and it is not uncommon to find weakness in this area as well. Paraesthesia in the lower leg, particularly on the top of the foot and ankle, also can accompany foot drop, although it is not in all instances.

A common yoga kneeling exercise, the Varjrasana has, under the name "yoga foot drop," been linked to foot drop.

Animal hoarding also causes many health problems for the people involved. Hoarders, by definition, fail to correct the deteriorating sanitary conditions of their living spaces, and this gives rise to several health risks for those living in and around hoarding residences. Animal hoarding is at the root of a string of human health problems including poor sanitation, fire hazards, zoonotic diseases, envenomation, and neglect of oneself and dependents.

Iron is needed for bacterial growth making its bioavailability an important factor in controlling infection. Blood plasma as a result carries iron tightly bound to transferrin, which is taken up by cells by endocytosing transferrin, thus preventing its access to bacteria. Between 15 and 20 percent of the protein content in human milk consists of lactoferrin that binds iron. As a comparison, in cow's milk, this is only 2 percent. As a result, breast fed babies have fewer infections. Lactoferrin is also concentrated in tears, saliva and at wounds to bind iron to limit bacterial growth. Egg white contains 12% conalbumin to withhold it from bacteria that get through the egg shell (for this reason, prior to antibiotics, egg white was used to treat infections).

To reduce bacterial growth, plasma concentrations of iron are lowered in a variety of systemic inflammatory states due to increased production of hepcidin which is mainly released by the liver in response to increased production of pro-inflammatory cytokines such as Interleukin-6. This functional iron deficiency will resolve once the source of inflammation is rectified; however, if not resolved, it can progress to Anaemia of Chronic Inflammation. The underlying inflammation can be caused by fever, inflammatory bowel disease, infections, Chronic Heart Failure (CHF), carcinomas, or following surgery.

Reflecting this link between iron bioavailability and bacterial growth, the taking of oral iron supplements in excess of 200 mg/day causes a relative overabundance of iron that can alter the types of bacteria that are present within the gut. There have been concerns regarding parenteral iron being administered whilst bacteremia is present, although this has not been borne out in clinical practice. A moderate iron deficiency, in contrast, can provide protection against acute infection, especially against organisms that reside within hepatocytes and macrophages, such as malaria and tuberculosis. This is mainly beneficial in regions with a high prevalence of these diseases and where standard treatment is unavailable.

The underlying disorder must be treated. For example, if a spinal disc herniation in the low back is impinging on the nerve that goes to the leg and causing symptoms of foot drop, then the herniated disc should be treated. If the foot drop is the result of a peripheral nerve injury, a window for recovery of 18 months to 2 years is often advised. If it is apparent that no recovery of nerve function takes place, surgical intervention to repair or graft the nerve can be considered, although results from this type of intervention are mixed.

Non-surgical treatments for spinal stenosis include a suitable exercise program developed by a physical therapist, activity modification (avoiding activities that cause advanced symptoms of spinal stenosis), epidural injections, and anti-inflammatory medications like ibuprofen or aspirin. If necessary, a decompression surgery that is minimally destructive of normal structures may be used to treat spinal stenosis.

Non-surgical treatments for this condition are very similar to the non-surgical methods described above for spinal stenosis. Spinal fusion surgery may be required to treat this condition, with many patients improving their function and experiencing less pain.

Nearly half of all vertebral fractures occur without any significant back pain. If pain medication, progressive activity, or a brace or support does not help with the fracture, two minimally invasive procedures - vertebroplasty or kyphoplasty - may be options.

Ankles can be stabilized by lightweight orthoses, available in molded plastics as well as softer materials that use elastic properties to prevent foot drop. Additionally, shoes can be fitted with traditional spring-loaded braces to prevent foot drop while walking. Regular exercise is usually prescribed.

Functional electrical stimulation (FES) is a technique that uses electrical currents to activate nerves innervating extremities affected by paralysis resulting from spinal cord injury (SCI), head injury, stroke and other neurological disorders. FES is primarily used to restore function in people with disabilities. It is sometimes referred to as Neuromuscular electrical stimulation (NMES)

The latest treatments include stimulation of the peroneal nerve, which lifts the foot when you step. Many stroke and multiple sclerosis patients with foot drop have had success with it. Often, individuals with foot drop prefer to use a compensatory technique like steppage gait or hip hiking as opposed to a brace or splint.

Treatment for some can be as easy as an underside "L" shaped foot-up ankle support (ankle-foot orthoses). Another method uses a cuff placed around the patient's ankle, and a topside spring and hook installed under the shoelaces. The hook connects to the ankle cuff and lifts the shoe up when the patient walks.

Recurrence rate is higher in aspirated cysts than in excised ones. Ganglion cysts have been found to recur following surgery in 12% to 41% of patients.

A six-year outcome study of the treatment of ganglion cysts on the dorsum (back) of the wrist compared excision, aspiration, and no treatment. Neither excision nor aspiration provided long-term benefit better than no treatment. Of the untreated ganglion cysts, 58% resolved spontaneously; the post-surgery recurrence rate in this study was 39%. A similar study in 2003 of ganglion cysts occurring on the palmar surface of the wrist states: "At 2 and 5 year follow-up, regardless of treatment, no difference in symptoms was found, regardless of whether the palmar wrist ganglion was excised, aspirated or left alone."

The goal of investigation is the assessment of the severity of the ocular injury with an eye to implementing a management plan as soon as is required. The usual eye examination should be attempted, and may require a topical anesthetic in order to be tolerable. Many topical agents cause burning upon instillation. Proxymetacaine has been found to have the best tolerance.

Depending on the medical history and preliminary examination, the primary care physician should designate the eye injury as a "true emergency", "urgent" or "semi-urgent".

An "urgent" case must be treated within hours. This includes penetrating globe injuries; corneal abrasions or corneal foreign bodies; hyphema (must be referred); eyelid lacerations that are deep, involve the lid margin or involve the lacrimal canaliculi; radiant energy burns such as arc eye (welder's burn) or snow blindness; or, rarely, traumatic optic neuropathy.