Hair Loss - Types

There are more than 40 different types of hair loss known till date - some of them very common, others quite rare. Determining your type can help you understand how well your hair loss can respond to treatment. Few of the common varieties of hair loss are discussed here.

Androgenetic alopecia - This type of hair loss can affect both men and women, and is caused by the hormone dihydrotestosterone. It accounts for almost 95% cases of hair loss.

Androgenetic alopecia is genetically determined and can be classified as follows:

• Male-pattern baldness - This is typically characterised by a receding hairline at the temples and balding at the top of the head.
• Female-pattern baldness - This is characterised by hair loss and widening of the parting, along with reduction in the density as well as volume of the hair.

Involution alopecia - With advancing age, more hair follicles go into the resting phase. This leads to the gradual thinning of hair, termed as involution alopecia.

Telogen effluvium - Telogen effluvium is a condition that causes hair thinning and hair loss from all over the scalp. Hair loss is usually caused by a certain stressor or triggering factor that leads the hair to prematurely enter the resting phase and, thereafter, shed. This may sometimes occur even within three to six months after the initial stressor. The stressor could be anything like childbirth, sudden weight loss, starting or stopping of oral contraceptive pills, malaria, typhoid, etc.

The patient often complains of severe hair loss, with hair falling out in bunches while washing or combing.

Anagen effluvium - Anagen effluvium is characterised by the sudden loss of hair in very large numbers. It is called anagen effluvium because the hair falls directly from the growing stage. Usually, around 85% scalp hair falls at any time. Loss of hair in the growing phase can be quite severe. Therefore, most or all hair on the scalp can be lost. Anagen effluvium is mainly seen as a side effect of radiation or chemotherapy given for cancer treatment.

Drug-induced hair loss - This type of hair loss can be caused as a side effect of certain medications. Some of these medications are commonly used, namely, cholesterol-lowering drugs, blood thinners, oral contraceptives, medicines for the treatment of gout, etc. It is important to let your doctor know if you are experiencing hair fall due to any medication so that it can be treated accordingly.

Alopecia areata - Alopecia areata is an autoimmune condition characterised by the sudden, patchy loss of hair. The onset of alopecia areata can be quite sudden, with rapid hair loss.

This condition may also be linked to the imbalance of the thyroid hormone or sudden and extreme stress. Hair can be lost from the entire scalp (alopecia totalis) or from the entire body (alopecia universalis). The condition is known to vary, and often, old patches can fill up while new ones still appear.

The silver lining is that there is no damage to the hair follicle. With the right treatment, all the hair can potentially grow back.

Traction alopecia - Traction alopecia is caused because of traction or pull on the hair. This may be caused by certain hair styles that pull at the roots, namely, tight braids and buns, or because the hair gets pulled by the wrong use of clips, tight rubber bands, etc.

Trichotillomania - Trichotillomania is a psychological disorder more frequently occurring in children, which makes them develop a tendency to pull out their own hair, leading to hair loss.

Other reasons for hair loss are as follows:

• due to the presence of infections - syphilitic alopecia (caused by systemic syphilis), tinea capitis (a localised fungal infection of the scalp); and
• due to generalised atrichia - caused by the presence of a recessive hairless gene; this is an extremely rare form of hair loss.