Alopecia ( /ˌæləˈpiːʃə/, from Classical Greek ἀλώπηξ, alōpēx) means loss of hair from the head or body. Alopecia can mean baldness, a term generally reserved for pattern alopecia or androgenic alopecia. Compulsive pulling of hair (trichotillomania) can also produce hair loss. Hairstyling routines such as tight ponytails or braids may induce Traction alopecia. Both hair relaxer solutions, and hot hair irons can also induce hair loss. In some cases, alopecia is due to underlying medical conditions, such as iron deficiency.
Generally, hair loss in patches signifies alopecia areata. Alopecia areata typically presents with sudden hair loss causing patches to appear on the scalp or other areas of the body. If left untreated, or if the disease does not respond to treatment, complete baldness can result in the affected area, which is referred to as alopecia totalis. When the entire body suffers from complete hair loss, it is referred to as alopecia universalis. It is similar to the effects that occur with chemotherapy.