Hair is made up of a protein called keratin, and it is produced in hair follicles in the outer layer of skin. Hair grows about 15 cm every year as new hair cells produced by follicles push the old cells out through the surface of the skin. On the human body, hair grows everywhere except the palms of hands, the soles of the feet, and over the eyelids. Many hair types are too small to see with naked eye. A human’s head is where the most hair is visible. On average an adult human has about 100,000 to 150,000 hairs on their head. It is normal to lose up to 100 of them a day. And at any one time, about 90% of the hair follicles on a human’s head is growing. Each follicle has its own life cycle which is divided into three phases. In the first anagen phase hair grows actively. This phase lasts between two to eight years. The catagen phase, second one, is a transitional phase at the end of the anagen phase where the hair converts into club hair. It lasts from two to three weeks. Finally the telogen phase is a resting phase that lasts about two to three months. At the end of the resting phase the hair is shed, a new hair replaces it to restart the cycle again. This life cycle can be influenced by age, disease, and a wide variety of other factors.aliquam. Ut est eros, porta eu ex ut, sagittis.