A person can lose up to 100 hairs per day. Hair grows about 5-10 mm per month and a single follicle’s growing phase lasts typically 3-6 years, after which the follicle enters a rest period of usually 3 months. During this time, the hair growth stops, the hair sheds and falls out. When the hair follicle reactivate, the new hair grows again for 3-6 years. In most cases, 85% of hair follicles are active while 15% are resting. If there is an illness or other extreme stress on the body, more hair follicles can go into a premature or prolonged rest. In all people, the number of active hair follicles decreases with age. There are three types of hair loss: male hair loss, diffuse hair loss, and hair loss in patches (alopecia areata).
Male hair loss
What causes excessive hair loss?
To date, it has been impossible to prevent hair loss. Male hair loss is called androgenic alopecia. It is by far the most common form of hair loss and affects an estimated 96% of all men and a growing number of women at some point in their life.
Male hair loss usually starts in their 20s or 30s, but can start as early as seventeen. Hereditary hair loss is gradual and follows a course that in many cases has a clear pattern (Hamilton-Norwood scale). It is usually more apparent around the temples as the hair-line creeps upward or in a part on the back on the crown where the hair starts growing thin and eventually becomes a bald spot. For women, more often the hair loss is diffuse and spread more evenly over the whole head.
Affected individuals inherited an increased susceptibility to the substance DHT (Dihydrotestosterozne), which is an activated testosterone. The hormone interacts with receptors at the bottom of the hair follicles and starts a negative chain reaction that, in simple terms, leads to reduced blood circulation and causes the hair follicle to shrink and then stop producing hair all together. The hair becomes thinner and thinner and eventually disappears completely.
How to get more hair
There are many ways to avoid hair loss problems and get more hair. Your doctor will probably ask you some questions about medicines you’re taking, whether you’ve had an illness recently, your diet, and if you take care of your hair. Everything from pills, ointments, sprays, paint, tattoos, toupees, wigs, hair transplants, and more have been tested. Some of these methods may actually increase hair loss, but none of them can create more hair.
Diffuse hair loss can cause as much as 40% of hair follicles to enter the resting phase and result in significant thinning of hair. This can occur 3-6 months after an infection or after great mental stress and is often associated with pregnancy.
Patchy hair loss (alopecia areata)
Alopecia areata is a disease that causes hair to be lost in patches. The hair loss is caused by the body’s own immune system attacking the hair follicles. For men, this can cause considerable hair loss. In most cases (about 60% of those with Alopecia areata), the disease appears before the age of 20, but it can take hold even in old age. Hair growth is restored to normal after 6 months once the immune system is regulated with medicine. Triggering factors are heredity, genetics, allergies and stress. Besides hair loss, Alopecia areata can also affect nails on fingers and toes. This usually manifests as small pits or stripes on the nails.