Actinic keratosis, also known as solar keratosis, is a type of sun-damaged skin that usually appears on areas frequently exposed to ultraviolet (UV) radiation, such as the lower thighs, forearms, hands, lips, bald scalp, and ears.

Agoraphobia is a mental health disorder characterized by an intense fear of situations or spaces where one might feel trapped. People with this condition often avoid crowded areas, public transportation, open spaces, and other places that make it difficult to escape.

Acute flaccid myelitis (AFM) is an uncommon and severe neurological illness that results in the weakness (flaccidity) of some muscles and reflexes. The symptoms can impair your capacity to breathe and appear quickly.

Alkaptonuria is a rare, inherited disorder that affects the body’s metabolism of specific amino acids. It is also known as AKU or Black Urine Disease. Alkaptonuria is an autosomal recessive genetic disorder where both parents must carry a defective gene copy for their child to be affected.

Anencephaly is a fatal congenital disability that happens when the brain, head, and scalp of the fetus don’t form while in the uterus. Babies born with this disease usually die within a few hours or days.

Angelman syndrome is a rare genetic abnormality that affects the nervous system. This disease is marked by delayed development, intellectual disability, severe speech problems, and ataxia, which causes trouble moving and staying balanced.

Angina is a type of chest pain when the heart doesn’t get enough blood. It is a sign that your cardiac muscles are not receiving adequate oxygen. People often describe the pain of angina as a feeling of squeezing, pressure, heaviness, or tightness in the chest.

Appendicitis is a common and potentially serious health emergency in which the appendix becomes inflamed and swollen with pus accumulation. The appendix is a small, finger-like outgrowth attached to the large intestine.