Since the time of the ancient civilizations of ancient Greece and Egypt, people have been trying out several concoctions which they hoped would cure baldness. These strange cures included pigeon droppings (prescribed by Hippocrates, the father of Western medicine), goat urine (used as a lotion by the great philosopher Aristotle on himself), crushed animal testicles (popular in ancient China), doing headstands (practised in ancient India, still believed there), rotten fat of snakes, crocodiles, lions, hippopotami and several other African animals (ancient Egyptian cure), powdered horse teeth (tried by none other than the great Cleopatra, on her lover Julius Caesar) and so forth.

Needless to say, none of these snake-oil and moon-juice cures actually worked. The ancients had certain theories about the causes of hair loss. Some thought that it was lack of blood supply to the scalp. Some surmised that it was a lack of proper nutrition for the hair roots. Yet others believed that the main thing was how the hair follicles got clogged by residual biological and environmental matters. They based their cures on these premises, and since none of the premises were true, their cures also fell flat.

So what actually causes hair loss? That is a difficult question which doesn't have a single, simple answer. There are more than one major cause, and the treatment must also vary accordingly.

First, there is male pattern baldness. This is perhaps the commonest cause of baldness in men. Have you ever noticed how most bald people are men? You have perhaps met a few thousand bald men in your life. How many bald women have you met or even seen? Perhaps one or two. Perhaps even none. Does baldness have something to do with sex then?

Indeed it does. The male sex hormone called testosterone is a complex biochemical substance that doesn't remain in the same form all the time. Through a certain metabolic process it gets changed into something that is known as dihydrotestosterone, or DHT for short.

This DHT plays a double role regarding scalp hair. When secreted in small amounts, it stimulates the growth of hair. But after a certain age, it starts to be manufactured in large doses in some individuals. And this excess of DHT has a very bad effect on the root cells and follicles of hair. These shrivel up and become loose under DHT's influence, causing hair to fall out very rapidly until baldness sets in. this is the main physiology behind the commonest type of baldness you can see in men.

A drug therapy has been developed to prevent or cure this type of baldness. The transformation of testosterone into DHT is mediated by a particular enzyme in our body, known as 5-alpha reductase. The drug called finasteride (commonly marketed as Propecia or Fincar) is able to block the action of 5-alpha reductase in a way that no or little DHT is produced from testosterone. Thus relieved of the debilitating effect of DHT, scalp hair starts to grow again normally.

Male pattern baldness, however, isn't the only type of hair loss. Another very common type is Alopecia areata, the reasons and treatment for which are completely different.

Alopecia areata is just a difficult name for spot baldness, in which certain areas of your body can lose their hair. Alopecia areata is normally limited to the hair growing on your scalp. In particularly bad cases, however, it can extend to you eyebrows and eyelashes, and nasal hair.

Doctors are of the general opinion that Alopecia areata is an auto-immune disease. Here's what that means, in plain English. The immune system of our own bodies (that system which fights diseases and kills infections) somehow becomes confused and starts to think that the hair follicles are foreign bodies trying to invade or harm us. Under this false conviction it attacks the hair roots, thus destroying them and causing our hair to fall out.

Some researchers think that Alopecia areata may also be caused by mental stress or excessive anxiety. However, no evidence in favor of this has yet been found.

There may not be any need to take medicine for Alopecia areata, because it often clears up on its own. But sometimes it may not, and in these cases the doctor will probably give you drugs to modify your immune system's response to the hair cells. These usually include certain steroids in the form of injections, tablets or ointments, or drugs of the minoxidil group.

Phototherapy is a new form of treatment for Alopecia areata that yields good results for some people. Hair implant is a costly method that may not be very suitable in Alopecia areata because the bald areas may grow or change shape rapidly.