Hair loss is a natural part of the cycle of hair growth. Each hair on your head will grow for two to three years before it starts a resting phase. At that time, it begins to fall out. Typically, about 90 percent of your hair is growing at any given time and about 10 percent is resting. That makes regular hair loss minimal and even difficult to notice.
When hair loss becomes excessive, resulting in thinning hair or bald patches on the scalp, factors other than the natural cycle of hair growth and loss are responsible.
Although hair loss is often associated with men of a certain age, it can affect men and women of any age. Hair loss can range from a receding hairline to thinning hair to complete hair loss. Hair loss can also affect eyelashes and eyebrows.
The medical name for hair loss is alopecia. There are several different types of alopecia including:
Alopecia areata, thought to be an autoimmune condition
Androgenetic alopecia, or hereditary hair loss
Cicatricial alopecia, caused by scar tissue in the hair follicles, for which the exact cause is poorly understood.
Telegen effluvium is a generalized hair loss that occurs approximately three months after a precipitating event, such as lupus, childbirth, or an acute illness. The event pushes hair prematurely into the resting state. There are a variety of potential causes of telogen effluvium. It can also be a side effect of certain medications.
Abnormal or excessive hair loss can be caused by factors such as:
Major stress or trauma—an illness or undergoing a major surgery
Fungal infections like ringworm
Eating disorders or nutritional deficiencies including protein and iron
Changes in hormone levels caused by thyroid disease
Changes in hormone levels caused by pregnancy or menopause
Side effects of medications including anticoagulants, antidepressants, birth control pills, and heart medications
Excessive vitamin A intake
Trichotillomania, a condition that causes people to pull out their hair
Genes, which can account for hereditary hair loss and hair thinning
Chemotherapy and other treatments for cancer
Hair damage from harsh chemicals/dyes used for styling
Oral, injected, and topical medications can help stop hair loss and promote new hair growth. Minoxidil is an over-the-counter topical hair treatment, and finasteride is a prescription topical medication. Other treatment options may include:
Anthralin and sulfasalazine, two psoriasis medications
Immune system suppressors such as cyclosporine
Removing hairless sections of the scalp (scalp reduction), then expanding the scalp to stretch skin with healthy hair growth
Replacing bald areas with parts of the scalp with healthy hair growth (scalp flaps)
You can also take steps to mask hair loss and balding spots. You may want to try a new hairstyle or experiment with fashion accessories such as scarves, hats, or even a wig. Some men opt to shave their entire head for a new look. Don't forget that your exposed scalp is vulnerable to sunburn and sun damage, so protect this skin with sunscreen and a hat any time you're outdoors.
If you're having trouble coping with the effects of hair loss, there are support groups available for both men and women; participating either in person or online can be helpful for dealing with the emotional aspects of this situation.