What is the health condition characterized by lack of hair?

Alopecia is the term used to describe hair loss, which can occur in various forms and can affect individuals of all ages. This condition can be localized, such as in alopecia areata, which results in patches of hair loss, or it can be more widespread, like alopecia totalis, where there is complete loss of hair on the scalp. It is important to note that alopecia can result from a range of factors, including genetic predisposition, autoimmune disorders, and other underlying health issues.

In contrast, hypertrichosis refers to excessive hair growth in areas where hair normally grows, while hirsutism involves excessive hair growth in women in areas typically seen in men, usually due to hormonal imbalances. Pseudotrichosis is not a commonly recognized term in medical literature, which further distinguishes alopecia as the accurate description of the condition characterized by lacking hair.