Asbestosis is a lung disease that occurs in people who inhale asbestos fibers and dust over a long period of time. Asbestos is a mineral that forms tiny and long-lasting fibers when it’s in the air. People in certain industries and occupations like construction, manufacturing, mining, milling, mechanics and electricians (especially those who worked before the 1970s) are most at …

Ascariasis is an infection in your intestines caused by a roundworm called Ascaris lumbricoides (A. lumbricoides). Like other parasites, these worms use the body of a host (like a human) to mature into egg-laying adults. The more the worms thrive, the more harm they can cause the host. A. lumbricoides is a kind of soil-transmitted helminth (STH). The worms living in someone’s gut lay eggs …

An atrial septal defect (ASD) is a hole in the atrial septum, which is the wall that separates your heart’s two upper chambers (atria). An ASD is a congenital heart defect (something you’re born with) that happens when the septum doesn’t form properly. It’s also called a “hole in the heart.” An ASD allows an abnormal shunt, meaning an abnormal passageway for blood that …

Aspergillosis is a term for an infection caused by several types of Aspergillus fungi (plural of fungus). Aspergillus is usually found outdoors, in dead leaves, plants, soil or compost. It’s occasionally found in moist environments indoors. Most people breathe in Aspergillus spores every day without getting sick. But in certain people, Aspergillus can cause allergic reactions, chronic lung conditions and invasive disease that spreads to your brain, kidneys, lungs …

Temporal arteritis (TA), or giant cell arteritis (GCA), is a form of vasculitis (inflammation of your blood vessels) that affects the arteries of your scalp, neck and arms. With this condition, most commonly your temporal arteries (the blood vessels near your temples) become inflamed (swollen) and constricted (narrowed). Your temporal arteries supply blood from your heart to your scalp, jaw muscles and optic (eye) …

Takayasu’s arteritis (also called Takayasu disease, pulseless disease or TAK) is an uncommon form of vasculitis or inflammation in your blood vessels. It affects your biggest arteries, like your aorta (the main blood vessel that leaves your heart) and arteries that branch off of your aorta and bring oxygenated blood from your heart to your body tissues. Affected arteries include the ones that supply …

Arthritis is a disease that causes damage in your joints. Joints are places in your body where two bones meet. Some joints naturally wear down as you age. Lots of people develop arthritis after that normal, lifelong wear and tear. Some types of arthritis happen after injuries that damage a joint. Certain health conditions also cause arthritis. Arthritis can affect any joint, but is …

Osteoarthritis is the most common type of arthritis (a condition that affects your joints). Healthcare providers sometimes refer to it as degenerative joint disease or OA. It happens when the cartilage that lines your joints is worn down over time and your bones rub against each other when you use your affected joints. Usually, the ends of bones in your joints are …

Gout is a form of inflammatory arthritis that causes pain and swelling in your joints. Gout happens when there’s a buildup of uric acid in your body. Gout most commonly affects your big toe joint. But it can affect other joints, including your: Knees. Ankles. Feet. Hands and wrists. Elbows. Gout symptoms come and go (recur) in episodes called flares or gout attacks. …