There are many kinds of hair loss, including what we call:
alopecia areata (patches of baldness that usually grow back);
telogen effluvium (rapid shedding after childbirth, fever, or sudden weight loss); and
traction alopecia (thinning from tight braids or ponytails).
All of these types of hair loss can be alarming but, fortunately, they are most often mild and temporary or reversible.
The majority of people who lose their hair, however, do it gradually and all through the scalp, with some emphasis on the frontal part. Doctors refer to this process as "androgenetic alopecia" which implies that a combination of hormones (andro-) and heredity (genetics) is needed to develop the condition.
Hair Loss in Men
What causes hair loss in men?Some men never go "bald" but everyone's hair thins out over the years. Despite much research, there's still only a little that men can do to slow down or reverse hair loss. I'm referring to garden-variety "male-pattern baldness." The medical term for that is "androgenetic alopecia," which means hair loss that you get when you have male hormones and a hereditary tendency to lose hair.
Sometimes, acute stress to the system (such as high fever, sudden weight loss, etc.) produces a sudden, rapid shedding of hair, where you find clumps of hair coming out all over the place. Although this syndrome (called telogen effluvium) is alarming, it actually is good news, because the body readjusts itself and most if not all the hair grows back. People whose loss of hair is inherited notice their hair is thinning but don't see very much hair actually coming out.
Once you think you're thinning, it's worth a check to be sure. Even men who never lose much hair develop some receding at both temples during adolescence. Boy's hairlines are straight across; adult men have more of an "M"-shape.
Clearing up the "Myths"
You inherit baldness through your mother's male relatives. Actually, baldness can come from either side of the family, or both. Looking at your family can give you at best, an educated guess about how you'll turn out.
Longer hair puts a strain on roots. Wrong. And hats choke off the circulation to the scalp causing hair loss. Nope, wrong again.
You lose up to 100 hairs per day normally - some days a lot more; others, a lot less. These hairs have finished their 3-year life span and are ready to be shed, then replaced. Finding hair on your comb or in the sink, therefore, does not necessarily mean you're going bald.
Shampooing does not accelerate balding; the hairs you find are just the ones ready to come out, and these will be replaced.
What treatments are there for hair loss in men? Many conditioners, shampoos, vitamins, and other products claim to help hair grow in some unspecified way. These are harmless but useless. To slow down hair loss, you have two options:
Minoxidil (brand name: Rogaine): This topical application is over-the-counter, no prescription is required. It works best on the crown, less on the frontal region. Available as a 2% solution, Rogaine may grow a little hair, but is better at holding onto what's still there. There are few side effects with Rogaine. The main problem with this treatment is the need to keep applying it twice a day, and most men get tired of it after awhile. In addition, Minoxidil mainly works on the crown (top of the head), not on the scalp on the front of the head, which is where baldness really bugs most men. This drug also comes in a higher strength, 5%, which may be a tad more effective, but is certainly much more expensive.
Finasteride (brand name: Propecia): This is a lower-dose version of a drug that shrinks prostates in middle-aged men. Propecia is by prescription and is taken once a day. Propecia seems to do a nice job of retaining hair, however, it may also grow or thicken hair a little. It's therefore the best treatment for men who still have enough hair to retain. One of the side effects is impotence, but it is uncommon and generally reversible. Taking Propecia once a day is easier that applying minoxidil, but the prospect of taking a pill daily for years doesn't sit well with some men. There's also the cost, about $50/month.
Stopping either Rogaine or Propecia puts you back where you would have been without them, but not worse off (except maybe financially).
What other options do I have for hair loss? Hairpieces, etc. You can always choose one of the time-honored ways to add hair temporarily; hairpieces or hair weaving, in which a mesh is attached to your remaining hair and artificial or human hair is woven to blend with your own. Either method can produce quite satisfactory results, but quality varies considerably and depends a great deal on how much you want to spend. Also, hairpieces and weaves stretch, oxidize, and loosen, which requires you to refresh or replace them (or in the case of hairpieces buy 2 or more at a time, to have on reserve.) Also, some stay on more securely than others during swimming and other activity. (How's that for a delicate euphemism?)
Surgical approaches include various versions of hair transplantation (taking hair from the back and putting it near the front) or scalp reduction (cutting away bald areas and stitching the rest together.). Check credentials carefully when consulting about these approaches since the skill of surgeons varies widely. If the doctor has limited experience, a poor esthetic sense, or if he or she transplants hairs that are destined to fall out anyway, results can be unnatural and unfortunate.
Finally, there is fatalism. Some bald men console themselves with adages like, "Grass doesn't grow on a busy street." That's fine, if it works for you.
Hair Loss in Women
Is hair loss in women different than men?
Hair loss in women also has an inherited (genetic) basis too, only not as much as men, and the loss is not as fast. Also, women tend not to have big bald spots; in general women's frontal hairline sticks around even to the bitter end. Thinning in women tends to be distributed throughout the scalp. Like men, when women first notice that their hair is thinner than it used to be (which can be in their early 20's in some families), they assume the process will gallop along and leave them bald in no time. In fact, it usually takes many years for thinning to become obvious to others.
Women start losing their hair later in life and almost never lose the frontal hairline, no matter how thin their hair gets (this is called female-pattern baldness.)
All of us develop thinning of our hair as we age. How thin our hair gets all depends on how much hair we start out with and the overall appearance of hair within the family. Women who still have full heads of hair often exclaim: "This is nothing--you should have seen how thick it used to be!"
Notions about baldness being inherited through the mother's family, just like stories about hats choking off follicles or long hair pulling on the roots, are just folklore.
Clearing up the "Myths"
Longer hair does not put a strain on roots.
You lose up to 100 hairs per day normally - some days a lot more; others, a lot less. These hairs have finished their 3-year life span and are ready to be shed, then replaced. Finding hair in your brush or in the sink, therefore, does not necessarily mean you're loosing all of your hair.
Shampooing does not accelerate hairloss; the hairs you find are just the ones ready to come out, and these will be replaced.
Don't stop coloring, perming, or conditioning your hair if you like the results of these processes. Hair styles that pull tightly can cause some hair loss, but hair coloring and "chemicals" do not.
What treatments are there for hair loss in women?
Ask your doctor about minoxidil (the generic name for Rogaine.) This is over-the-counter and available in 2% and 5% concentrations. It's something of a nuisance to apply but it helps conserve hair and may even grow some.
Propecia is a drug that helps men retain their hair but unfortunately has no use for women. Propecia is not safe for women of childbearing age and it just doesn't work for older women. This is unfortunate but, for the moment, this is the situation.
Surgical procedures like hair transplants can be useful for some women as well as men to "fill in" thinned-out areas
Adapted from MedicineNet