Causes of Hair Loss


Hereditary thinning is known by many different names: Androgenic, or androgen-dependent alopecia; common baldness; diffuse hair loss; and male or female pattern baldness.

Hereditary thinning is, by far, the most common kind of baldness. About half of all men over the age of 40 experience hair loss due to male pattern baldness. In fact, it is so common that many people think it is a normal part of the aging process.

Although hereditary baldness is not as common among women, as many as 20 million American women and 30% of all Caucasian women are affected by female pattern baldness.


People who inherit genes for baldness (or thinning) from either parent are likely to experience hair loss or thinning during their adult life.

Androgenic alopecia is also androgen dependent. Androgens are the hormones that stimulate the development of male sex characteristics. Testosterone is one type of androgen. Androgens induce alopecia by shortening the anagen phase and increasing the number of hairs that are in the telogen phase. Some women with Androgenetic alopecia have abnormally elevated levels of androgens in their bodies as a result of underlying ovarian or adrenal gland disorders.


Men with Androgenic alopecia typically have a receding hairline and moderate to extensive loss of hair, especially on the front and top of the head. The remaining hair tends to feel a little finer and shorter than normal. Male pattern baldness can start as early as the teenage years.

Women with Androgenetic alopecia experience overall thinning of their hair. For example, where there used to be five hairs, there may only be two. Most of the hair that's lost is on the crown of the head or at the hairline. Female pattern baldness usually starts around age 30 and becomes noticeable around age 40.

2. Alopecia Areata

Alopecia areata is a highly unpredictable, autoimmune skin disease resulting in the loss of hair on the scalp and elsewhere on the body. This common but very challenging disease affects approximately 1.7 percent of the population overall, including more than 4.7 million people in the United States alone. Due to the fact that much of the public is still not familiar with alopecia areata, the disease can have a profound impact on one's life and functional status, both at work and at school.

In alopecia areata, the affected hair follicles are mistakenly attacked by a person's own immune system (white blood cells), resulting in the arrest of the hair growth stage. Alopecia areata usually starts with one or more small, round, smooth bald patches on the scalp and can progress to total scalp hair loss (alopecia Totalis) or complete body hair loss (alopecia Universalis).

Alopecia areata occurs in males and females of all ages and races; however, onset most often begins in childhood and can be psychologically devastating. Although not life-threatening, alopecia areata is most certainly life-altering, and its sudden onset, recurrent episodes, and unpredictable course have a profound psychological impact on the lives of those disrupted by this disease.