When attempting to determine a person’s level of hair miniaturization and future patterns of balding, a miniaturization study is critical. This method reveals the rate of hair thinning in comparison with the surrounding normal healthy hair. The hair found on the back and sides of the head in most cases lasts a lifetime since these hairs are not affected by the hormone DHT, which is what is normally responsible for thinning. The thickness of these hairs is used to determine the proper size for the hairs on a person’s head.
When hair loss is active, it is due to the fact the hair follicles are going through a growth cycle and resting intervals where the hairs progressively get thinner. Eventually the hairs will become so fine they are undetectable to the naked eye. It is when a hair shaft loses its original thickness and continues thinning that miniaturization occurs.
At any particular time, hair can go through a cycling phase. This is when a hair shaft falls and another begins to grow from the same follicle only after a few weeks of the resting period. Since this cycle is not synchronized, only a small percentage of hairs will be put into the resting phase during any particular cycle. It is uncommon for this cycle to surpass 20% of the given hair shafts in any area.
When doing a microscopic evaluation, the percentage of miniaturized hairs are determined by area. This is to say, when looking at a particular area on the head (top, crown, corners, etc.) the amount of thinning can be estimated when seen under the microscope. Anything seen to be above the 20% miniaturization rate is considered abnormal and needs to be further evaluated and treated.
When a microscopic evaluation is performed, the pattern of hair loss will show the surgeon which areas the patient will eventually lose their hair, in order to take preventative measures to avoid future hair loss.
There are many other reasons for acute and extreme hair loss such as emotional trauma, seasons of high stress levels, or pregnancy (for women), which only last for a time and the hair eventually restores itself. These situations can be seen by repeating the study a few months after the events which caused the hair loss, have ended.