Cure imminent for thousands of years old ailment

They can have the hairs that grow out of my ears and nose!

Actually, hair loss is not a disease. As the chemical science can get a bit complicated it's easier to imagine that hair is a waste product from the body. It's made up of 18 amino acids that get pushed up (excreted) from the body through the hair follicle (an indentation in the skin). These form a chemical called keratin. Once the keratin has been pushed out about .05 mm it hardens and forms the hair. The hair is held together by cysteine bonds (one of the amino acids).

When a hair comes out of the head it's because the lining of the follicle comes away from the head. This gets replaced by another follicle but when it doesn't you don't get a new hair growing. This new research is working on producing follicles that will be compatible with your body.

That's not quite what happens but is much easier to understand.

The colour of hair comes from the melanin which forms about 1% of the structure. There are, basically, two types of melanin and your hair colour comes from the different proportions and concentrations of those two. When you go 'grey' it's because the body is no longer producing the melanin. Hair doesn't really go grey, it goes white/silver. It looks grey when you are still producing some melanin so some hairs are dark and others are white/silver.

Whether you have straight or curly hair depends on the shape of the follicle. Once again, rather simplistically, straight hair comes from round follicles and wavy hair comes from oval follicles.

Hair is very tough but can get damaged by alkaline products. So, washing your hair in detergent isn't a good idea.