A: Miniaturization is the decrease in hair shaft length and diameter that results from the action of DHT on healthy, full thickness terminal hairs. The hairs eventually become so small that they resemble the fine, vellus hair normally present in small numbers on the scalp and body. Miniaturized hairs have little cosmetic value. Eventually miniaturized hairs will totally disappear. Twenty percent miniaturization refers to the observation, under densitometry, that 20% of the hairs in an area show some degree of decreased diameter.

In the evaluation of candidates for hair transplantation, we use the 20% as a rough guide to include all hairs that are not full thickness terminal hairs. Of course we are most interested in the presence of intermediate diameter hairs – i.e. those whose diameters are somewhere between terminal and vellus and are clearly the result of DHT. I don’t know if one can tell the difference on densitometry between vellus hairs, fully miniaturized hairs and senile alopecia. The partially miniaturized population is most revealing.

Miniaturization in the recipient scalp (i.e. the balding areas on the front top and crown that we perform hair transplants into) is present in everyone with androgenetic hair loss. Miniaturization in the donor area, however, is less common (in men). It means that the donor area is not stable and will not be permanent. Men with more than 20% of the hair in the donor area showing miniaturization are generally not good candidates for hair transplant surgery.

A: Low Level Laser Therapy (LLLT) is based on the scientific principle of photobiotherapy.

Photobiotherapy occurs when laser light, absorbed by cells, causes stimulation of cell metabolism and improved blood flow.

Although the exact mechanism by which lasers promote hair growth is still unknown, they appear to stimulate the follicles on the scalp by increasing energy production and partially reversing the miniaturization process leading to thicker hair shafts and a fuller look.

A: Hair shafts are not alive (only the follicle is) so cutting the hair will not affect its growth.

A: If medication, such as finasteride, is successful it can thicken hair by increasing the diameter of the existing hair shafts. Although the cosmetic benefits can be dramatic in a person with significant hair loss, a hair transplant can not restore hair to its original density, since it only moves the existing hair around and does create new hair.

When hair cloning technology is available, this will change as a person’s donor supply will be increased.

A: Dying hair is a very common practice and hair loss in women who are 48 years old is also very common. The fact that the two have occurred together does not necessarily imply that there is a cause and effect relationship.

Women who are already losing hair often go to a great deal of effort to disguise this fact with dying, bleaching, and perming. These procedures, particularly if too aggressive, or done too frequently, can cause weakening and increased fragility of the hair shaft and increased hair breakage may result. This is more common if the hair is already fine in texture. This breakage is frequently interpreted as “hair loss” and it certainly does result in a significant loss of hair bulk, although the follicle itself is not damaged.

When there is a relationship between the hair dye and hair loss, it is usually an inflammatory/allergic or irritant reaction. If severe, there may be an actual burn. In these cases, there would be a history of redness and swelling.

An inflammatory reaction could cause hair loss but it would be unusual to damage follicles enough to produce scarring – although this occasionally does occur.

A scalp biopsy is often helpful to sort out these cases.