Defining Different Types of Hair Loss

How do you define hair loss? Do you consider you're balding when you've lost 5 hairs, 5,000, or 50,000? Can you slow the balding process, stop it altogether, or should you just increase your baseball hat collection and live with it?

Hair falls out of your head every single day, at a rate of about 100 to 150 hairs if you are a Caucasian (Asians lose 80-120 per day and Africans 60-100 per day). You aren't going bald if your hair is coming out at these rates because that is the rate that new hair grows up from the scalp. If the hair that falls out isn't replaced by the same number of new hairs, then you have a balding problem.

Hair loss isn't noticeable in the average person until more than 50 percent is lost, which is around 50,000 hairs, more or less. Why does hair loss occur at all? You were born with your hair, and by simple logic, you should die with it, right? Not one organ in the human body dies as a natural course of aging, yet hair follicles commit mass suicide over time.

Other human organs may change over time and become less functional, but they don't disappear altogether. Is hair loss a type of genetic adaptation? No one knows. This article looks at the different types and causes of hair loss, including the cause of 99 percent of all cases of male balding: male pattern baldness.

Telling the difference between genetic baldness and everything else

There's more than one category of hair loss. Can your doctor tell just by looking at you what kind of hair loss you have? Yes, sometimes. Hereditary hair loss patterns, the most common type of hair loss in men, have developed into a classical clinical descriptive science. Genetic hair loss appears in distinct patterns, and these patterns are almost 100-percent diagnostic for male pattern baldness.

In women, balding patterns also exist, and a knowledgeable doctor may be able to tell what's causing the hair loss just by looking.

Examining uniform hair loss

A small segment of people lose scalp hair uniformly (diffusely), rather than losing hair in specific scalp areas. Uniform hair loss isn't as easy to detect as other types of hair loss because the hair is steadily lost all over the head. It's much easier to detect a bald spot resulting from hair loss in a specific area of the scalp from diseases that cause uniform hair loss to the normal genetics of that particular person.

Hair loss occurs normally and usually occurs at the end of one of the normal hair cycles that all hair goes through. These hair cycles are as follows:

Anagen: The growth stage, which lasts three years on average but may be as short as a year and as long as seven years).

Catogen: The stage when the hair prepares to go into the next phase and undergoes changes in its anatomy, falling out at the end of this part of the cycle.

Telogen: The sleep phase when a percentage of the hair disappears (lasts from two to five months on average). About 10 percent of all of the hairs on our head are in the telogen part of the cycle at any one time.

At the end of the telogen phase, a new hair bud appears, signaling the beginning of anagen.

The hair apparatus starts off producing a baby hair below the skin, which grows longer and longer until the final terminal hair (a full mature hair reflective of what we style every day when we comb out hair) emerges from the pore in the skin. In some adults, the anagen phase may never start, signaling that the hair follicle may have died. If a new hair doesn't grow to replace the lost hair, the total hair count drops.

Hair grows in natural occurring groups called follicular units (FU). A single FU contains from one to four terminal hairs and one vellus hair (a fine hair amidst the clump of terminal hairs). When a hair isn't replaced after its telogen phase, the number of hairs in the FU decreases, but the number of FUs remains the same. So an FU starting with four terminal hairs may end up with only two or three terminal hairs as we age or as we undergo some form of balding. When this happens across the whole scalp, the total hair count decreases proportionally.

The older the patient is, the more likely it is that doctors see this uniform hair loss process. About one third of men over age 70 have this diffuse hair loss, which is called senile alopecia. The name doesn't reflect the mental status of those afflicted, but rather it essentially means that the condition is most common in the elderly. Because hair also becomes finer with age, severe thinning reflects a loss of both hair bulk (in each hair shaft) and hair densities. There's no cure for senile alopecia.

Young men may experience uniform hair loss in the form of a condition called diffuse unpatterned alopecia (DUPA). Doctors believe that DUPA and senile alopecia are similar but for the age of occurrence. DUPA impacts men in their 20s and 30s and doesn't seem to be responsive to drugs used to treat the classic type of male patterned hair loss.