The Hair Circle
While you have a full head of hair, each hair grows for about four years. This growing period (anagen) is followed by a short transitional phase and then a resting period (telogen) of about two or three months, after which the hair is lost from the scalp and a new hair takes its place within the same follicle. Of course, your hairs are not all synchronized to grow and fall together. If this were the case, you would temporarily lose all your hair at one time - as does happen with some animals that molt. Instead, the hairs grow and fall in a random fashion so that your normal daily loss of hair goes unnoticed.
What Is Excessive Hair Loss?
Excessive hair loss simply means more hair than you normally lose. For some people, the loss is about 50 hairs whereas, for others, the daily loss may be about 100. Usually, you lose a few more hairs when you shampoo - due to the agitation of the hairs by your fingers - and fewer hairs during the time following the shampoo. The hairs you lose during shampooing or combing etc are in the resting stage. In other words, they are ready to fall out. Therefore, whether you shampoo daily or once, your total weekly loss will be exactly the same. People with excessive hair loss should not cut down on their frequency of shampooing.
Trichologists can accurately calculate your rate of loss of hair by examining microscopically several hairs that have been depilated from the scalp. The percentage of hairs in the resting (telogen) phase of the hair cycle is normally about 15%. Therefore, a percentage of 20% or more would strongly suggest excessive hair loss. A person with excessive hair loss must find out the reason for this hair loss.
Hair Is A Thermometer of Health
Excessive hair loss from the entire scalp is termed diffuse hair loss or telogen effluvium. It results as a reaction to a disturbance within the body. The disturbance may have been a temporary one to which the body quickly adjusts, or it may be a more serious one which the body has difficulty coming to terms with. Whichever is the case, diffuse hair loss is an important sign that your body recently went out of balance and may still be out of balance. The good news is that, with diffuse hair loss, the lost hair is always replaced and the excessive loss will either correct itself or will slow to normal once the underlying cause has been pinpointed and corrected.