Causes of Hair Loss

Genes : that are located on the X or Y-chromosomes are call sex-linked. Genes on the other 22 pairs of chromosomes are called autosomal. It is felt that the genes governing common baldness are autosomal. This means that the baldness trait can be inherited from the mother's side of the family or the father's side. The genes involved in androgenetic alopecia are felt to be dominant.

Hormones : These same hormones that cause acne and beard growth can also signal the beginning of baldness. The presence of androgens; testosterone, and its related hormone DHT, cause some follicles to regress and die. In women, hormones with androgenic activity cause hair loss as well. In addition to the testicles, the adrenal glands located above each of our kidneys, produce androgenic hormones, and this would be similar in both sexes. In females, there is an additional source of hormones that can affect hair, the ovaries. The hormone felt to be directly involved in androgenetic alopecia is actually dihydrotestosterone (DHT) rather than testosterone. Among other effects, DHT decreases the length of the anagen (growing) cycle, and increases the telogen (resting) phase, so that with each new cycle the hair shaft becomes progressively smaller.

Time: The reaction also requires time of exposure of susceptible hair follicles to the hormone for hair loss to begin. Hair loss does not occur all at once or in a steady, straight-line progression. Hair loss is cyclical.

Stress : It is important to note that stress generally causes the type of hair loss referred to as telogen effluvium. Telogen effluvium is the reversible shed-ding of hair in the resting phase when the body senses that it needs to divert its energies elsewhere (pregnancy would be a good example of this).