We lose an average of 50 to 100 hairs per day, but since the scalp holds some 100,000 hairs, our daily loss doesn’t usually cause any thinning of the hair. Hair does tend to become thinner as we age, however. And in some people, the growth of new hair may be slowed, or the loss of hair accelerated, resulting in localized or complete baldness.
Hair loss can be hereditary, or it can be caused by certain types of medication or an underlying condition. Anyone can experience accelerated hair loss – men, women, and children. Some take it in stride, while others prefer to hide it with intricate hairstyles, makeup, hats or scarves. Some also try to treat the hair loss with medication or a surgical procedure (e.g. hair transplant).
Normal hair physiology
A hair follicle is a structure located at the base of the hair. It contains a blood vessel that nourishes hair growth. All our hair follicles are there at birth. Throughout our lives, each follicle produces the growth and loss of hair in regular cycles. The growth phase lasts two to three years. The hair then enters a rest phase that lasts three to four months, after which the hair falls out and a new cycle begins. On any given day, 80 to 90 percent of hairs are in a growth phase, 50 to 100 hairs fall out (with an equal number starting a new cycle), and the remaining hairs are in the rest phase.
Why do we lose our hair?
Hair loss can be caused by various phenomena. Some occur suddenly, others gradually. Some affect only the scalp, others all the hair on the body. Some are temporary, others permanent.
The most common cause of hair loss is a hereditary hormonal problem that produces a shorter growth phase, which causes the hair follicle to become shorter and thinner, bringing about a gradual loss of hair. The phenomenon is called androgenic alopecia (or, commonly, male-pattern baldness) and it mainly occurs in men, although women may also be affected. Heredity influences the age of onset of hair loss, as well as how quickly it occurs.
There are also many other causes of alopecia:
- Hormonal changes associated with pregnancy, childbirth or menopause can cause temporary hair loss in women.
- Thyroid problems, scalp infections, certain medications (e.g. cancer treatments) and certain skin diseases can cause alopecia.
- Physical stress such as sudden weight loss or high fever, or emotional stress such as losing a loved one, can also cause hair loss. This loss is usually temporary.
- Poor nutrition (anorexia or over-dieting), particularly an iron or protein deficiency, can also aggravate the problem.
- Certain individuals suffering from a mental illness have an irresistible urge to pull on their head or body hair, leaving certain areas hairless.
- Certain hairdos requiring that hair be pulled very tight can cause temporary hair loss, as can the incorrect use of hair colours or straighteners.
There are a few pharmaceutical drugs that can help counter hair loss:
- Minoxidil is a liquid solution that is applied to the scalp twice a day to slow hair loss. This product promotes hair growth by extending the growth phase and stimulating more follicles to produce hair. It isn’t a miracle product, as it only works for 30 to 40 percent of men and women who use it. It appears mainly effective when the hair loss has been occurring for under five years, when it affects mainly the top of the head and isn’t larger than 10 centimeters in diameter.
This product must be used regularly for at least six months to determine whether it is working. If it is having an effect, the loss of hair should slow down within two months, and there should be an increase in hair growth as of the fourth to eighth month of use. The effect stabilizes after 12 to 18 months of use, but the treatment has to be continued in order for the effects to persist. The adverse effects are minor, with skin irritation being the most common. Since the product can be absorbed, it is important that it be applied to intact, lesion-free skin.
- Finasteride is a medication used to treat androgenic alopecia. It is offered in tablet form and acts by reducing the production of a hormone associated with hair loss. It should not be used by women who could become pregnant. It is usually well tolerated at the doses recommended to treat alopecia. At higher doses, it may cause adverse effects such as erectile dysfunction or reduced libido.
- There are also surgical treatments for alopecia. Various approaches are possible, depending on the location and extent of the hair loss, and the amount of hair available in other areas. For example, strips of scalp from areas with good hair coverage can be grafted onto bald (or balding) areas. When the bald area isn’t too large, it can sometimes be removed and the rest of the non-balding scalp be sewn together.
- Lastly, wigs are a simple way of masking temporary or permanent hair loss. There are quality lifelike products on the market now.
If you have any questions about hair loss, don’t hesitate to speak to your doctor or pharmacist!