Avascular necrosis is a condition in which bone tissue dies because it does not receive enough blood. It is also known as osteonecrosis. When blood flow to a bone is reduced or stopped, tiny breaks can form in the bone structure, eventually causing the bone to weaken and collapse. This process may take months or even years to develop. An …

Aspergillosis is an infection caused by a mold known as aspergillus, which is a type of fungus commonly found in the environment. The illnesses caused by aspergillosis usually affect the respiratory system, though symptoms and severity can vary widely. Some forms are mild, while others can be life-threatening. Aspergillus mold is found both indoors and outdoors. Most strains are harmless …

Asthma is a long-term condition in which the airways of the lungs become inflamed, narrow and swollen, and may produce extra mucus. These changes make breathing difficult and can lead to coughing, wheezing and shortness of breath. For some people, asthma causes only mild and occasional symptoms. For others, it can be a serious condition that interferes with daily activities …

An asthma attack is a sudden worsening of asthma symptoms. Asthma is a long-term condition that affects the airways in the lungs, causing them to become narrow and making breathing difficult. During an asthma attack, symptoms such as coughing, wheezing, chest tightness and trouble getting enough air can develop or rapidly worsen. These symptoms occur because the muscles around the …

Asthma is a long-term (chronic) lung disease that affects your airways. Your airways are the tubes that carry air in and out of your lungs. When you have asthma, you can’t get air into your lungs because your airways swell and get too narrow. Like a pinched straw, this makes it hard for you to breathe, which can cause wheezing, coughing and chest …

Exercise-induced asthma, also known as exercise-induced bronchoconstriction, is a condition in which physical activity triggers narrowing of the airways, making breathing difficult. It can occur in people with or without chronic asthma and is commonly triggered by vigorous exercise, especially in cold or dry air. Symptoms usually begin during exercise or shortly after stopping and can interfere with physical performance …

Gout is a type of inflammatory arthritis caused by the buildup of uric acid crystals in the joints. Uric acid forms when the body breaks down substances called purines, which are found naturally in the body and in certain foods. When uric acid levels become too high, crystals can accumulate in joints, leading to sudden and severe pain. Gout commonly …

Juvenile idiopathic arthritis is a chronic inflammatory condition that affects children under the age of 16. It is characterized by persistent joint inflammation that lasts for at least six weeks and has no identifiable cause. The condition can involve one or multiple joints and may also affect other parts of the body, such as the eyes or internal organs. Juvenile …

Psoriatic arthritis is a type of arthritis. It usually affects people who have psoriasis or a biological family history of psoriasis. Arthritis is a common disorder that affects your joints. It causes pain and inflammation in and around your joints. Psoriasis causes inflammation in your skin. Psoriasis rashes are patches of discolored skin covered with scales. These thick, scaly areas are called plaques. …

Reactive arthritis is an inflammatory joint condition that develops as a reaction to an infection in another part of the body, most commonly the gastrointestinal or genitourinary tract. The arthritis itself is not caused by direct infection of the joints but by an abnormal immune response triggered by the initial infection. Reactive arthritis often affects the knees, ankles, and feet …