Androgenetic Alopecia

Androgenetic Alopecia, commonly referred to as “male pattern baldness” is caused by a combination of genetics and hormones called androgens. It affects both men and women but is generally noticed in men earlier than in women. This condition affects approximately 40 million men in North America.

Though both men and women can suffer from Androgenetic Alopecia, it presents differently for each sex. Most men will experience hair loss at the hairline (receding hairline) as well as at the crown of the head (bald spot). Learn more about Hair Loss in Men

Androgenetic Alopecia in women deviates from the patterns seen in most men. Women suffering from the condition will experience widespread hair loss wherein hair loss is first experienced at the top of the scalp (in the part of the hair) rather than the hairline and crown. This pattern has often been referred to as “Female Pattern Baldness”, and affects most women experiencing hair loss. Learn more about Hair Loss in Women

Androgenetic Alopecia often begins at puberty, but may not be evident until several years later. Individuals experiencing hair loss will notice that their hair loss will progress through various stages. They will also notice that they may experience some periods of accelerated hair loss, and some periods of minimal hair loss. These fluctuations make it difficult to pinpoint how much hair a person will lose and how long their hair loss will continue.

What causes Androgenetic Alopecia?

There are many misconceptions that hair loss is caused by poor circulation, clogged hair follicles, frequent shampooing, the wearing of hats or helmets, or overexposing your hair to chemical processes such as perming or colouring. While there are relatively uncommon causes of hair loss, such as thyroid disease, iron deficiency, high fever, and stress, the overwhelming majority of male hair loss is caused by heredity.  This condition is referred to as Androgenetic Alopecia.

Genetics

There are several variables that are responsible for causing male pattern baldness, including genes and hormones. Genetics are a determining factor in hair loss and can be passed on by either parent, or even from both sides. This genetic transfer is not predictable and may skip a generation, or affect only a sibling or two in the family. The common belief that baldness is genetically transferred only from the mother’s side of the family is incorrect. The genetics of male pattern baldness is complicated and not completely understood but is believed to involve more than one gene. These genes make the hair on your head more susceptible to hormones in your body that affect hair loss.

Hormones

Hormones are chemicals produced in the body that control and regulate specific cells or organs. Androgens are a group of hormones present in both men and women that are responsible for masculine characteristics. Testosterone is an androgen, and is part of the complex reaction that results in hair loss.

Dihydrotestosterone (DHT) is a by-product of testosterone that is produced in the scalp by an enzyme called 5-alpha reductase. Individuals with a particular genetic makeup have inherited hair follicles that are sensitive to DHT. These are the individuals who suffer from Androgenetic Alopecia.

In patients with genetically sensitive hair follicles, DHT binds to receptors on the hair follicles and alters the hair’s natural growth cycle. The DHT slows the stage during which the hair grows, known as the Anagen phase. The DHT also lengthens the phase during which hair is dormant, known as the Telogen phase. Hairs in the Telogen phase are more susceptible to being shed.

Therefore, the combination of genetics and the hormone DHT affects the hair’s growth cycle and contributes to hair loss. While hair loss is often difficult to reverse, there are treatment options available to both men and women suffering from hair loss.