Normal Hair Growth
About 90 percent of the hair on a person’s scalp is growing at any one time. The growth phase lasts between two and six years. Ten percent of the hair is in a resting phase that lasts two to three months. At the end of its resting stage, the hair is shed. When a hair is shed, a new hair from the same follicle replaces it and the growing cycle starts again. Scalp hair grows about one-half inch a month. As people age, their rate of hair growth slows. Most hair shedding is due to the normal hair cycle, and losing 50-to-100 hairs per day is no cause for alarm.
Causes of Excessive Hair Loss
Improper Hair Cosmetic Use/Improper Hair Care
Many men and women use chemical treatments on their hair, including dyes, tints, bleaches, straighteners and permanent waves. These treatments rarely damage hair if they are done correctly. However, the hair can become weak and break if any of these chemicals are used too often. Hair can also break if the solution is left on too long, if two procedures are done on the same day, or if bleach is applied to previously bleached hair. If hair becomes brittle from chemical treatments, it’s best to stop until the hair has grown out.
Hairstyles that pull on the hair, like ponytails and braids, should not be pulled tightly and should be alternated with looser hairstyles. The constant pull causes some hair loss, especially along the sides of the scalp.
Shampooing, combing and brushing too often can also damage hair, causing it to break. Using a cream rinse or conditioner after shampooing will make it easier to comb and more manageable. When hair is wet, it is more fragile, so vigorous rubbing with a towel and rough combing and brushing should be avoided. Don’t follow the old rule of 100 brush strokes a day as that damages hair. Instead, use wide toothed combs and brushes with smooth tips.
Hereditary Thinning or Balding
Hereditary balding or thinning is the most common cause of hair loss. The tendency can be inherited from either the mother’s or father’s side of the family.
Women with this trait develop thinning hair but do not become completely bald. The condition is called androgenetic alopecia and it can start in the teens, twenties or thirties. There is no cure, although medical treatments have recently become available that may help some people. One treatment involves applying a lotion, minoxidil, to the scalp twice a day. Another treatment for men is a daily pill containing finasteride, a drug that blocks the formation of the active male hormone in the hair follicle.
In this type of hair loss, hair usually falls out, resulting in totally smooth, round patches about the size of a coin or larger. It can, rarely, result in complete loss of scalp and body hair. This disease may affect children or adults of any age. The cause of alopecia areata is unknown. Apart from the hair loss, affected persons are generally in excellent health. In most cases, the hair regrows by itself. Treatments include topical medications, a special kind of light treatment, or in some cases pills.
When a women is pregnant, more of her hairs will be growing. However, after a woman delivers her baby, many hairs enter the resting phase of the hair cycle. Within two to three months, some women will notice large amounts of hair coming out in their brushes and combs. This can last one to six months but resolves completely in most cases.
High Fever, Severe Infection, Severe Flu
Illnesses may cause hairs to enter the resting phase. Four weeks to three months after a high fever, severe illness or infection, a person may be shocked to see a lot of hair falling out. This shedding usually corrects itself.
Both an over-active thyroid and an under-active thyroid can cause hair loss. Your physician can diagnosis thyroid disease with laboratory tests. Hair loss associated with thyroid disease can be reversed with proper treatment.
Inadequate Protein in Diet
Some people who go on crash diets that are low in protein or have severely abnormal eating habits may develop protein malnutrition. The body will save protein by shifting growing hairs into the resting phase. Massive hair shedding can occur two to three months later. Hair can then be pulled out by the roots fairly easily. This condition can be reversed and prevented by eating the proper amount of protein and, when dieting, maintaining adequate protein intake.
Some prescription drugs may cause temporary hair shedding. Examples include some of the medicines used for the following: gout, arthritis, depression, heart problems, high blood pressure, or blood thinner. High doses of vitamin A may also cause hair shedding.
Some cancer treatments will cause hair cells to stop dividing. Hairs become thin and break off as they exit the scalp. This occurs one to three weeks after the treatment. Patients can lose up to 90 percent of their scalp hair. The hair will regrow after treatment ends. Patients may want to get wigs before treatment.
Birth Control Pills
Women who lose hair while taking birth control pills usually have an inherited tendency for hair thinning. If hair thinning occurs, a woman can consult her gynecologist about switching to another birth control pill. When a women stops using oral contraceptives, she may notice that her hair begins shedding two or three months later. This may continue for six months when it usually stops. This is similar to hair loss after the birth of a child.
Low Serum Iron
Iron deficiency occasionally produces hair loss. Some people don’t have enough iron in their diets or may not fully absorb iron. Women who have heavy menstrual periods may develop iron deficiency. Low iron can be detected by laboratory tests and can be corrected by taking iron pills.
Major Surgery/Chronic Illness
Anyone who has a major operation may notice increased hair shedding within one to three months afterwards. The condition reverses itself within a few months but people who have a severe chronic illness may shed hair indefinitely.
Fungus Infection (Ringworm) of the Scalp
Caused by a fungus infection, ringworm (which has nothing to do with worms) begins with small patches of scaling that can spread and result in broken hair, redness, swelling, and even oozing. This contagious disease is most common in children and oral medication will cure it.
Hair Pulling (Trichotillomania)
Children and sometimes adults will twist or pull their hair, brows or lashes until they come out. In children especially, this is often just a bad habit that gets better when the harmful effects of that habit are explained. Sometimes hair pulling can be a coping response to unpleasant stresses and occasionally is a sign of a serious problem needing the help of a mental health professional.