Donor Hair Density
Donor hair density is one of the important factors a Doctor will consider when making their assessment as to your suitability as a hair transplant candidate, the density is measured by how many follicular units (FU´s) there are per cm²; FU´s are natural groupings of hairs, generally 1-4 hairs per FU.
The hair density is best measured under magnification by a simple handheld device to more sophisticated software that can save the results; with the hair density will alter depending on the area of the head/scalp with the greatest density found around the occipital or back of the head.
In the occipital (back of the head) the number of FU´s cm² typically ranges between 65 and 85, and will reduce around the sides of the scalp; an average hair density around the scalp is approximately 75FU´s cm² but can rise to over 100 FU´s cm² in some cases and as low as 50.
As important as a good starting hair density is, it must be accompanied by a good hair count per Follicular Unit. With an average hair to FU count being 2.2 hairs per FU, much less than this could impair the result short and long term, especially if hair loss progresses.
Donor hair density is a vital element that needs to be calculated when planning a hair transplant, coupled with the average number of hairs per follicular unit.
Whenever you have a personal consultation with a Doctor ensure this is measured.