March 2, 2012
Dear Mayo Clinic:
Is it true that you inherit genes for baldness from your mother's side of the family? Is there anything that can be done to prevent or slow hair loss?
Actually, patterns of baldness are inherited from many genes, which can come from both sides of the family. So, to assess your chances for hair loss, look at all relatives in your mother's and father's families. Although age-related baldness has no permanent fix, if you are concerned about hair loss, treatments may help.
Hair goes through a cycle of growth and rest. In general, the growth phase of an individual hair on the scalp lasts about two to three years. During this time, hair grows a little less than one-half inch a month. After that, the resting phase lasts a few weeks. At the end of the resting phase, the hair strand falls out and a new one begins to grow in its place.
Most people have about 100,000 hairs on their head. Normally about 75 to 100 hairs are shed each day. We tend not to think about that daily hair loss until we notice thinning hair or we start to worry about aging. Gradual hair thinning is a normal part of aging. However, hair loss may lead to baldness when the rate of shedding starts to outpace the rate of regrowth or when new hair is thinner than the hair shed.
In male- and female-pattern baldness, the time of hair growth shortens, and the hairs are not as thick or sturdy as they once were. With each growth cycle, the hairs become less firmly rooted and fall out more easily. Heredity likely plays a key role in hair loss. A history of baldness on either side of your family increases your risk of balding. Heredity also affects the age when hair loss begins, how fast it develops, and the pattern and extent of baldness.
If hair loss bothers you, treatment options are available. First, minoxidil (Rogaine) is an over-the-counter medication for baldness that can regrow some of the hair you lost, as well as help keep the hair you have. It comes in liquid or foam, and should be applied to the scalp twice a day.
The key to this medication's effectiveness is applying it consistently. If you forget for several days or take a break from it for a while, you will likely shed the hair that the medication was helping you keep.
New hair resulting from minoxidil use may be thinner and shorter than previous hair. But, for some people, hair growth can be enough to hide bald spots and help the new hair blend with existing hair. Up to 12 weeks of treatment may be required for new hair to start growing. That growth stops if minoxidil is discontinued.
The drug finasteride (Propecia) can also slow hair loss and may foster new hair growth. Finasteride is a pill taken daily that is available by prescription. This medication is for men only, because it can cause serious health problems in women. Finasteride poses significant danger to women of childbearing age. If you're pregnant, you shouldn't even handle crushed or broken finasteride tablets because absorption of the drug may cause birth defects in male fetuses.
If these treatments do not slow hair loss to your satisfaction, other alternatives, including surgical procedures, may be available to help cover baldness. Talk to your doctor to review the options and discuss what may work best for you.
ā Dawn Davis, M.D., Dermatology, Mayo Clinic, Rochester, Minn.