Hair loss, also known as alopecia, is a common condition in which a person loses hair from their scalp or other parts of the body. Hair loss can be caused by a variety of factors, such as genetics, hormonal changes, aging, stress, certain medical conditions, and certain medications. The most common type of hair loss is androgenetic alopecia, which is inherited and affects both men and women. Other types of hair loss include alopecia areata, which causes patchy hair loss, and telogen effluvium, which is temporary hair loss due to stress or illness. Treatments for hair loss depend on the cause and may include medications, hair transplant surgery, or lifestyle changes.