Lymph node enlargement is recognized as a common sign of infectious, autoimmune, or malignant disease. Examples may include:

- Reactive: acute infection ("e.g.," bacterial, or viral), or chronic infections (tuberculous lymphadenitis, cat-scratch disease).

- The most distinctive sign of bubonic plague is extreme swelling of one or more lymph nodes that bulge out of the skin as "buboes." The buboes often become necrotic and may even rupture.

- Infectious mononucleosis is an acute viral infection caused by Epstein-Barr virus and may be characterized by a marked enlargement of the cervical lymph nodes.

- It is also a sign of cutaneous anthrax and Human African trypanosomiasis

- Toxoplasmosis, a parasitic disease, gives a generalized lymphadenopathy ("Piringer-Kuchinka lymphadenopathy").

- Plasma cell variant of Castleman's disease - associated with HHV-8 infection and HIV infection

- Mesenteric lymphadenitis after viral systemic infection (particularly in the GALT in the appendix) can commonly present like appendicitis.

Less common infectious causes of lymphadenopathy may include bacterial infections such as cat scratch disease, tularemia, brucellosis, or prevotella.

- Tumoral:

- Primary: Hodgkin lymphoma and non-Hodgkin lymphoma give lymphadenopathy in all or a few lymph nodes.

- Secondary: metastasis, Virchow's Node, neuroblastoma, and chronic lymphocytic leukemia.

- Autoimmune: systemic lupus erythematosus and rheumatoid arthritis may have a generalized lymphadenopathy.

- Immunocompromised: AIDS. Generalized lymphadenopathy is an early sign of infection with human immunodeficiency virus (HIV), the virus that causes acquired immunodeficiency syndrome (AIDS). "Lymphadenopathy syndrome" has been used to describe the first symptomatic stage of HIV progression, preceding a diagnosis of AIDS.

- Bites from certain venomous snakes such as the pit viper

- Unknown: Kikuchi disease, progressive transformation of germinal centers, sarcoidosis, hyaline-vascular variant of Castleman's disease, Rosai-Dorfman disease, Kawasaki disease, Kimura disease

Lymphadenopathy or adenopathy is disease of the lymph nodes, in which they are abnormal in size, number, or consistency. Lymphadenopathy of an inflammatory type (the most common type) is lymphadenitis, producing swollen or enlarged lymph nodes. In clinical practice, the distinction between lymphadenopathy and lymphadenitis is rarely made and the words are usually treated as synonymous. Inflammation of the lymphatic vessels is known as lymphangitis. Infectious lymphadenitides affecting lymph nodes in the neck are often called scrofula.

The term comes from the word lymph and a combination of the Greek words , "adenas" ("gland") and , "patheia" ("act of suffering" or "disease").

Lymphadenopathy is a common and nonspecific sign. Common causes include infections (from minor ones such as the common cold to dangerous ones such as HIV/AIDS), autoimmune diseases, and cancers. Lymphadenopathy is also frequently idiopathic and self-limiting.

Mediastinal lymphadenopathy or mediastinal adenopathy is an enlargement of the Mediastinal lymph nodes

Splenomegaly is a common symptom of infectious mononucleosis and health care providers may consider using abdominal ultrasonography to get insight into the enlargement of a person's spleen. However, because spleen size varies greatly, ultrasonography is not a valid technique for assessing spleen enlargement and should not be used in typical circumstances or to make routine decisions about fitness for playing sports.

Infectious mononucleosis is generally self-limiting, so only symptomatic or supportive treatments are used. The need for rest and return to usual activities after the acute phase of the infection may reasonably be based on the person's general energy levels. Nevertheless, in an effort to decrease the risk of splenic rupture experts advise avoidance of contact sports and other heavy physical activity, especially when involving increased abdominal pressure or the Valsalva maneuver (as in rowing or weight training), for at least the first 3–4 weeks of illness or until enlargement of the spleen has resolved, as determined by a treating physician.

According to present research, PFAPA does not lead to other diseases and spontaneously resolves as the child gets older, with no long term physical effects.

However, PFAPA has been found in adults and may not spontaneously resolve.

PFAPA syndrome typically resolves spontaneously. Treatment options are used to lessen the severity of episodes. Treatment is either medical or surgical.

One treatment often used is a dose of a corticosteroid at the beginning of each fever episode. A single dose usually ends the fever within several hours. However, in some children, they can cause the fever episodes to occur more frequently. Interleukin-1 inhibition appears to be effective in treating this condition.

Surgical removal of the tonsils appears to be beneficial compared to no surgery in symptom resolution and number of future episodes. The evidence to support surgery is; however, of moderate quality.

Treatments for sarcoidosis vary greatly depending on the patient. At least half of patients require no systemic therapy. Most persons (>75%) only require symptomatic treatment with non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or aspirin. For persons presenting with lung symptoms, unless the respiratory impairment is devastating, active pulmonary sarcoidosis is observed usually without therapy for two to three months; if the inflammation does not subside spontaneously, therapy is instituted.

Major categories of drug interventions include glucocorticoids, antimetabolites, biologic agents especially monoclonal anti-tumor necrosis factor antibodies, and more recently, specific antibiotic combinations and mesenchymal stem cells. If drug intervention is indicated, a step-wise approach is often used to explore alternatives in order of increasing side effects and to monitor potentially toxic effects.

Corticosteroids, most commonly prednisone or prednisolone, have been the standard treatment for many years. In some people, this treatment can slow or reverse the course of the disease, but other people do not respond to steroid therapy. The use of corticosteroids in mild disease is controversial because in many cases the disease remits spontaneously.

People with sarcoidosis may have a range of symptoms that do not correspond with objective physical evidence of disease but that still decrease quality of life.

Physical therapy, rehabilitation, and counseling can help avoid deconditioning, and improve social participation, psychological well-being, and activity levels. Key aspects are avoiding exercise intolerance and muscle weakness.

Low or moderate-intensity physical training has been shown to improve fatigue, psychological health, and physical functioning in people sarcoidosis without adverse effects. Inspiratory muscle training has also decreased severe fatigue perception in subjects with early stages of sarcoidosis, as well as improving functional and maximal exercise capacity and respiratory muscle strength. The duration, frequency, and physical intensity of exercise needs to accommodate impairments such as joint pain, muscle pain, and fatigue.

Neurostimulants such as methylphenidate and modafinil have shown some effectiveness as an adjunct for treatment of sarcoidosis fatigue.

Treatments for symptomatic neuropathic pain in sarcoidosis patients is similar to that for other causes, and include antidepressants, anticonvulsants and prolonged-release opioids, however only 30–60% of patients experience limited pain relief.

Specific treatment depends on the location, type, and stage of the tumour. Treatment may involve surgery, radiotherapy, or chemotherapy, alone or in combination. This is a specialised area which requires the coordinated expertise of ear, nose and throat (ENT) surgeons (Otorhinolaryngologists) and Oncologists. A severely affected patient may require a laryngectomy, the complete or partial removal of the vocal cords.

The first line treatment for polymyositis is corticosteroids. Specialized exercise therapy may supplement treatment to enhance quality of life.

Polymyositis, like dermatomyositis, strikes females with greater frequency than males.

Incidence is five in 100,000 (12,500 new cases per year) in the USA. The American Cancer Society estimated that 9,510 men and women (7,700 men and 1,810 women) would be diagnosed with and 3,740 men and women would die of laryngeal cancer in 2006.

Laryngeal cancer is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH). This means that laryngeal cancer affects fewer than 200,000 people in the U.S.

There is very little information written by, and for patients with GLILD. However, interest in the condition is increasing and multi-centre studies such as STILPAD are in progress.

There are no current guidelines available on the investigation and management of GLILD and evidence is restricted to retrospective case series. Because of the association with poorer outcomes, and because some patients develop advanced lung disease, most specialists now recommend treatment in early disease, but this is always an individual decision between patient and health-care team. Many centres screen for the development of GLILD (and other lung complications) using regular lung function tests and CT scans.

Studies of GLILD have been conducted in patients on background immunoglobulin replacement. In a cohort of 59 CVID patients with granulomatous disease, 30 (51%) of whom had lung involvement, complete remission of disease was obtained in 5 of 25 attempts using corticosteroids (three patients), methotrexate (1 patient) and cyclophosphamide (1 patient). Partial responses were also seen with rituximab and hydroxychloroquine. In contrast, a second report suggested poor response to corticosteroids alone, but a good response to 18-months treatment with rituximab and azathioprine in seven patients. Bone marrow transplantation has been attempted. Immunosuppression has been associated with development of opportunistic infection and other predictable side effects, and the balance of risks and benefits of therapy must be carefully weighed in each case. This may be best achieved by joint working between immunology, respiratory, radiology and pathology specialists, working as part of a multi-professional team with the patient.

With early treatment, rapid recovery from the acute symptoms can be expected, and the risk of coronary artery aneurysms is greatly reduced. Untreated, the acute symptoms of Kawasaki disease are self-limited ("i.e." the patient will recover eventually), but the risk of coronary artery involvement is much greater. Overall, about 2% of patients die from complications of coronary vasculitis. Patients who have had Kawasaki disease should have an echocardiogram initially every few weeks, and then every one or two years to screen for progression of cardiac involvement.

Laboratory evidence of increased inflammation combined with demographic features (male sex, age less than six months or greater than eight years) and incomplete response to IVIG therapy create a profile of a high-risk patient with Kawasaki disease. The likelihood that an aneurysm will resolve appears to be determined in large measure by its initial size, in which the smaller aneurysms have a greater likelihood of regression. Other factors are positively associated with the regression of aneurysms, including being younger than a year old at the onset of Kawasaki disease, fusiform rather than saccular aneurysm morphology, and an aneurysm location in a distal coronary segment. The highest rate of progression to stenosis occurs among those who develop large aneurysms. The worst prognosis occurs in children with giant aneurysms. This severe outcome may require further treatment such as percutaneous transluminal angioplasty, coronary artery stenting, bypass grafting, and even cardiac transplantation.

A relapse of symptoms may occur soon after initial treatment with IVIG. This usually requires rehospitalization and retreatment. Treatment with IVIG can cause allergic and nonallergic acute reactions, aseptic meningitis, fluid overload and, rarely, other serious reactions. Overall, life-threatening complications resulting from therapy for Kawasaki disease are exceedingly rare, especially compared with the risk of nontreatment. Also, evidence indicates Kawasaki disease produces altered lipid metabolism that persists beyond the clinical resolution of the disease.

Kawasaki disease affects boys more than girls, with people of Asian ethnicity, particularly Japanese and Korean people, most susceptible, as well as people of Afro-Caribbean ethnicity. The disease was rare in Caucasians until the last few decades, and incidence rates fluctuate from country to country.

Currently, Kawasaki disease is the most commonly diagnosed pediatric vasculitis in the world. By far, the highest incidence of Kawasaki disease occurs in Japan, with the most recent study placing the attack rate at 218.6 per 100,000 children <5 years of age (about one in 450 children). At this present attack rate, more than one in 150 children in Japan will develop Kawasaki disease during their lifetimes.

However, its incidence in the United States is increasing. Kawasaki disease is predominantly a disease of young children, with 80% of patients younger than five years of age. About 2,000-4,000 cases are identified in the U.S. each year (9 to 19 per 100,000 children younger than 5 years of age).

In the United Kingdom, estimates of incidence rate vary because of the rarity of Kawasaki disease. However, it is believed to affect fewer than one in every 25,000 people. Incidence of the disease doubled from 1991 to 2000, however, with four cases per 100,000 children in 1991 compared with a rise of eight cases per 100,000 in 2000.

In the continental United States, Kawasaki Disease is more common during the winter and early spring, boys with the disease outnumber girls by ≈1.5–1.7:1, and 76% of affected children are <5 years of age.

Leukemia is rarely associated with pregnancy, affecting only about one in 10,000 pregnant women. Treatment for chronic lymphocytic leukemias can often be postponed until after the end of the pregnancy. If treatment is necessary, then giving chemotherapy during the second or third trimesters is less likely to result in pregnancy loss or birth defects than treatment during the first trimester.

Research in 2008 is comparing different forms of bone marrow transplants to determine which patients are the best candidates and which approach is best in different situations.

Researchers at the Abramson Cancer Center of the University of Pennsylvania School of Medicine reported preliminary success in the use of gene therapy, through genetically modified T cells, to treat CLL. The findings, which were published in August 2011, were based on data from three patients who had modified T cells injected into their blood. The T cells had been modified to express genes that would allow the cells to proliferate in the body and destroy B cells including those causing the leukemia. Two patients went into remission, while the presence of leukemia in the third patient reduced by 70%. One of the patients had been diagnosed with CLL for 13 years, and his treatment was failing before he participated in the clinical trial. One week after the T cells were injected, the leukemia cells in his blood had disappeared. The T cells were still found in the bloodstream of the patients six months after the procedure, meaning they would be able to fight the disease should leukemia cells return. This was the first time scientists "have used gene therapy to successfully destroy cancer tumors in patients with advanced disease".

Research is also investigating therapies targeting B cell receptor signalling. Syk inhibitor fostamatinib is in trials.

LINES was first described in a 54-year-old male with history of hypothyroidism who presented to an urgent care facility with bilateral axillary adenopathy and severe malaise. Incision and drainage of the nodes was performed and he was discharged home with sulfamethoxazole/trimethoprim for presumed Methicillin-resistant Staphylococcus aureus (MRSA) infection.

The patient subsequently developed a temperature of 37.5°C, expressed rigors, and night sweats. He returned to the ED the next day and on further history admitted to 3 weeks of “snorting 6-8 lines of coke a day” and smoking marijuana every evening to “come down.” He was hospitalized and treated with cefepime, doxycycline, and fluconazole empirically. The next day erythematous painful papules appeared on his trunk, arms, face, and ears. Blood cultures were negative. There was prominent necrosis of the malar region, nose, and lips with complete sparing of the back. Skin biopsy revealed extensive small vessel thrombosis throughout the superficial and deep dermal plexuses with perivascular mononuclear inflammatory infiltrate and a few neutrophils surrounding the vessels. ESR was elevated at 35 mm/hour; cardiolipin IgM was weakly positive at 16.3;C4 was decreased at 10 mg/dl; antinuclear antibodies were negative and p-ANCA was reactive. Coagulation studies were within normal limits. There was an elevated d-dimer of 17.54 mg/mL and platelets were slightly decreased. The patient’s urine drug screen was positive for cannabis but not cocaine.

Methylprednisolone was started and wound care was initiated. Epidermal necrosis then evolved to myonecrosis extending from midthigh to the foot which necessitated below knee amputation of the right extremity.The patient also required allografts to his chest and abdomen and autografts to his face and left lower extremity.

In 2011 a team of physicians from University of South Florida Morsani College of Medicine in Tampa, FL (under the attending service of John T. Sinnott, MD FACP) recognized an association of skin necrosis with use of levamisole adulterated cocaine. The mnemonic LINES was coined to name the syndrome because the name was descriptive, reminds one of a “line” of cocaine, and is easily remembered. Thus it is self exemplifying.

Mansonelliasis (or mansonellosis) is the condition of infection by the nematode "Mansonella".

The disease exists in Africa and tropical Americas, spread by biting midges or blackflies. It is usually asymptomatic.

Mansonelliasis, in the form of "M. ozzardi", was first documented in 1897.

Surgical correction of inguinal hernias is called a hernia repair. It is not recommended in minimally symptomatic hernias, for which watchful waiting is advised, due to the risk of post herniorraphy pain syndrome. Surgery is commonly performed as outpatient surgery. There are various surgical strategies which may be considered in the planning of inguinal hernia repair. These include the consideration of mesh use (e.g. synthetic or biologic), open repair, use of laparoscopy, type of anesthesia (general or local), appropriateness of bilateral repair, etc. Laparoscopy is most commonly used for non-emergency cases, however, a minimally invasive open repair may have a lower incidence of post-operative nausea and mesh associated pain. During surgery conducted under local anaesthesia, the patient will be asked to cough and strain during the procedure to help in demonstrating that the repair is without tension and sound.

Constipation after hernia repair results in strain to evacuate the bowel causing pain, and fear that the sutures may rupture. Opioid analgesia makes constipation worse. Promoting an easy bowel motion is important post-operatively.

Surgical correction is always recommended for inguinal hernias in child.

Emergency surgery for incarceration and strangulation carry much higher risk than planned, "elective" procedures. However, the risk of incarceration is low, evaluated at 0.2% per year. On the other hand, surgery has a risk of inguinodynia (10-12%), and this is why males with minimal symptoms are advised to watchful waiting. However, if they experience discomfort while doing physical activities or they routinely avoid them by the fear of pain, they should seek surgical evaluation. For female patients, surgery is recommended even for asymptomatic patients.

There is currently no medical recommendation about how to manage an inguinal hernia condition in adults, due to the fact that, until recently, elective surgery used to be recommended. The hernia truss is intended to contain a reducible inguinal hernia within the abdomen. It is not considered to provide a cure, and if the pads are hard and intrude into the hernia aperture they may cause scarring and enlargement of the aperture. In addition, most trusses with older designs are not able effectively to contain the hernia at all times, because their pads do not remain permanently in contact with the hernia. The more modern variety of truss is made with non-intrusive flat pads and comes with a guarantee to hold the hernia securely during all activities. Although there is as yet no proof that such devices can prevent an inguinal hernia from progressing, they have been described by users as providing greater confidence and comfort when carrying out physically demanding tasks. A truss also increases the probability of complications, which include strangulation of the hernia, atrophy of the spermatic cord, and atrophy of the fascial margins. This allows the defect to enlarge and makes subsequent repair more difficult. Their popularity is likely to increase, as many individuals with small, painless hernias are now delaying hernia surgery due to the risk of post-herniorrhaphy pain syndrome. The elasticised pants used by athletes also provide useful support for the smaller hernia.