Normally there are between 100,000 and 150,000 hair roots on the human head. These hairs do not grow independently from one another. They are arranged in groups of 1 to 4 called follicular groups. There are about 50,000 to 65,000 follicular groups in human hair.
90% of the terminal hair of the person is in the growth process at any given time. This period is called anagen phase and lasts 2 to 7 years, with an average of 3 years. Growth stops in the catachanical stage that lasts for 2-3 weeks. The remaining hair (10%)stays in the resting state called telogen, and for a normal individual, this phase lasts 3-4 months.
When the hair is in the relaxation phase, the elongation stops, the bulb separates from the papillae and hair falls as it is combed and new hair emerges underneath. When the hair falls spontaneously, a white mass appears at the tip of the hair. Most people think it’s the center of hair growth, but it’s just the bottom of the hair. The dermal papilla stays under the skin.
The hair growth rate is 0.44mm per day. Each follicle passes through this cycle about 10-20 times on average in human life.
People lose about 100 strings of hair a day. Whenever we brush our hair, we can see hair some on the brush. If the proportion of hair loss that you see on your combs, brushes, sinks or tubers is high, your hair may be falling due to a disease or side effect of a drug which you are using. Common genetic baldness is caused not by intense hair loss but by short and thin hair that replaces the fallen hair. This process is called “miniaturization”.