Alopecia Areata is a disease that affects thousands of individuals. It's an autoimmunie disease that disturbs the hair follicles where the hair grows. Anyone can have alopecia areata.
Not to be confused with androgenetic alopecia, alopecia areata is a condition where the body's immune system
- which usually protects the body from infection - actually ATTACKS the hair follicles.
If you're finding smooth, roundish bald patches on your scalp, then alopecia areata is the likely cause.
Up to 1 in 5 cases of alopecia is due to a genetic predisposition to the condition - in other words, if one or both of your parents had it, then this may make you somewhat more likely to develop it too.
It may also be more likely to occur if you have an existing autoimmune condition like diabetes or hyperthyroidism (overactive thyroid).
There are many causes of scalp hair loss, and they do differ in men and women. Studies show that losing up to 100-150 hairs per day is normal. Human hair naturally grows in three phases: anagen, catagen, and telogen. The hairs that are shed daily are often in the resting or late phase in the hair cycle. Normally, about 10% of the scalp hairs are in the resting or telogen phase at any time. These hairs are not growing and are getting prepared for cyclic shedding.
Only your doctor can give you a firm diagnosis of alopecia, which is reached after tests which may include a scalp biopsy, examination of the hairs themselves or - in some cases - blood tests.
What is Alopecia Areata?
The human body is covered with approximately five million hair follicles, each independently cycling through the three phases of the hair-growth cycle. Lips, soles of the feet and palms of the hands are among the limited places on the human body where hair is not found. Unlike many animals whose hair growth patterns are controlled by the change of season and the resulting variation in length of day, human hair growth occurs randomly. Although hair is dead material (mainly the protein keratin), it and the follicles that produce it are part of the body's epidural or skin structure. Therefore, the three growth cycles are as follows:
Three Phases of Hair Growth
Anagen ~ Growth Phase
Approximately 80 percent to 90 percent of a healthy individual's hair is in the anagen phase, a time when the hair is actively growing. During this phase the hair grows about 1 cm every 28 days. The amount of time a hair spends in the anagen phase controls how long the hair will grow.
Catagen ~ Transitional Phase
The catagen phase is a short period of transition between the anagen and telogen phases. This phase lasts only one to three weeks. The catagen phase involves a period of major cell death, and only a remnant of the hair follicle remains at the completion of this phase. However, near the end of the catagen stage, movement of the dermal papilla occurs, setting the stage for re-growth.
Telogen ~ Resting Phase
The resting phase follows the catagen phase and normally lasts about 5-6 weeks. During this time the hair does not grow, but stays attached to the follicle while the dermal papilla stays in a resting phase below. Approximately 10-15 percent of all hairs are in this phase at any one time. The telogen phase lasts approximately two or three months, a resting phase before the growth phase returns.