Behcet disease is a type of autoimmune disease. It causes inflammation of blood vessels. It’s a rare disease in the United States, but it is more common in the Middle East and Asia. It’s more common in people in their 20s to 40s, but it can happen at any age.

A Baker cyst (popliteal cyst) is a fluid-filled sac that forms behind the knee.

Peripheral neuropathy is a type of damage to the nervous system.

Bacterial endocarditis is a bacterial infection of the inner layer of the heart or the heart valves. Read on to learn about the cause, symptoms, diagnosis, and treatment.

Aspiration is when something enters your airway or lungs by accident. It may be food, liquid, or some other material. This can cause serious health problems, such as pneumonia. Aspiration can happen when you have trouble swallowing normally. This is called dysphagia.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a disease of the heart muscle. In this disease, fatty fibrous tissue replaces normal heart muscle. This interrupts normal electrical signals in the heart and may cause irregular and potentially life-threatening heart rhythms. The heart also becomes weaker over time leading to heart failure.

A joint dislocation is when there is an abnormal separation between the bones of a joint. When this happens in your ankle joint, it's known as an ankle dislocation. It is a severe injury.

Aniridia is a serious and rare eye disorder in which the iris is partly or completely gone.

Acute bacterial rhinosinusitis (ABRS) is an infection of both your nasal cavity and sinuses. It's caused by bacteria. Here's what you need to know about this condition.

Parkinson disease is a movement disorder that can cause muscles to tighten and become rigid. It can make it hard to walk and engage in daily activities.