Baldness is determined by multiple genetic factors. It cannot be categorically stated that baldness follows the mother's line or anyone else's, or that it skips generations.
Both men and women lose hair density as they age. Men develop a typical pattern of baldness, associated with the presence of the male hormone testosterone. Men who do not produce testosterone (because of genetic abnormalities or castration) do not develop this pattern of baldness. The use of steroids during adolescence and young adulthood may accelerate the effects of testosterone on baldness. Women also develop a characteristic pattern of hair loss. See male-pattern baldness; female-pattern baldness.
Occurring most often on the scalp, alopecia usually develops gradually and may be all over (diffuse) or patchy.
Usually baldness is not caused by a disease but is genetic and permanent. Inherited or "pattern baldness" affects many more men than women. About 25% of men begin to bald by the time they are 30 years old, and about two-thirds are either bald or have a balding pattern by age 60.
On average, about 100 hairs are lost from the head every day. The average scalp contains about 100,000 hairs (blondes 140,000, brunettes 155,000 and redheads only 85,000).
Each individual hair survives for an average of 4.5 years, during which time it grows about half an inch a month. Usually in its 5th year, the hair falls out and is replaced within 6 months by a new one. Genetic baldness is caused by the body's failure to produce new hairs and not by excessive hair loss.
COMMON CAUSES
heredity and aging (male-pattern baldness; female-pattern baldness)
hormonal changes (for example, thyroid disease)
a serious illness
fever
medication such as cancer chemotherapy or too much vitamin A
excessive shampooing and blow-drying
emotional or physical stress
nervous habits such as continual hair pulling or scalp rubbing
burns
radiation therapy
alopecia areata (a pattern of diminished hair on the head and beard areas)
tinea capitis
traction alopecia (a self-induced reduction of hair by pulling it out)
trichotillomania
HOME CARE
For hair loss caused by illness (such as fever), radiation therapy, or medication use, no treatment is necessary. The hair will usually grow back when illness has ended or therapy has stopped. A wig, hat, or other covering may be desired until the hair grows back.
For hair loss due to heredity, the medication Rogaine (minoxidil), which requires a prescription, has shown some positive effect. However, results are mixed and there are good results in less than 10% of the cases. Also, Rogaine can be expensive.
Punch graft hair transfer done by a physician is a surgical approach to transferring hair from one part of the head to another. It is somewhat painful and expensive, but usually permanent.
CALL YOUR HEALTH CARE PROVIDER IF...
hair is present in the involved area but fails to grow out normally.
continual hair-pulling is suspected.
the skin under the involved area is abnormal.
WHAT TO EXPECT AT YOUR HEALTH CARE PROVIDER'S OFFICE
The medical history will be obtained and a physical examination performed.
Medical history questions documenting hair loss in detail may include:
location and pattern
What part of the body is losing hair?
Is there a pattern to the hair loss (male-pattern baldness; female-pattern baldness)?
medical history
Have you had a recent illness?
Have you had a high fever recently?
hair care habits
Do you dye your hair?
Do you blow dry your hair?
How often do you shampoo your hair?
What kind of shampoo, hair spray, gel, or other product do you put on your hair?
emotional state
Have you been under unusual stress?
Do you have nervous habits that include hair pulling or scalp rubbing?
accidents and emergencies history
Have you ever been involved in an accident that affected your scalp or hair in any way?
other
What other symptoms are also present?
What medications are being taken?
An examination of the hair and scalp are usually enough to diagnose the nature of the problem.
Diagnostic tests that may be performed (but are rarely needed) include: