Hair Loss (Alopecia) in Women

A hair's growth cycle includes a phase known as ‘anagen' in which the hair continues to grow for up to 3 years, a phase known as ‘catagen' in which the hair rests for up to 3 months and a phase known as ‘telogen' in which the hairs are shed at the end of the 3 month resting period. There are a number of common causes of alopecia in women which affect these phases.

Telogen Effluvium

Telogen effluvium refers to a general, and usually temporary, shedding of hair. It can occur on the scalp and/or body and leaves the hair looking thinner. This can happen suddenly at any age following a shock to the body's physical or hormonal systems and can be caused by, for example, childbirth, a surgical operation, sudden weight loss, an illness, stress, or due to medication. The problem usually resolves itself after a few months.

During the telogen phase of the hair's growth cycle, the hair remains in the hair follicle until it is pushed out by a new hair which has entered the anagen phase. Normally, approximately fifteen per cent of hair on the head is in the telogen phase. However, a sudden shock to the system can cause a larger percentage than normal of hairs on the head or body to enter the telogen phase simultaneously. If this happens, at the end of the 3 month teleogen cycle a greater than normal number of hairs will be pushed out leading to a temporary thinning of the hair which resolves itself when the new hairs in the anagen phase grow long enough to become apparent.