Each hair grows independently of other hairs. There are three periods of hair growth. Not all hairs experience the same period of growth at the same time. The period of active growth is called Anagen. During this period, hair grows at a rate of about three tenths millimeters a day, or one centimeter a month. About 85 percent of hair follicles are going through this process at any given time. This period can last from two to six years.
The Catagen period of hair growth comes next. It is then that hair growth begins to slow down. This period usually lasts two or three weeks. Finally, hair growth comes to a complete stop and the hairs begin to fall out. This period is known as Telogen. It affects about 15 percent of all hairs at a time.
On average, a person loses between 50 and 100 hairs every day. Since each hair grows at a different rate, this process is overlooked. Once the Telogen period has ended, the hair growth process begins again.
So what happens when a person has trouble growing hair or suffers from hair loss? Your genes control how fast or how long your hair will grow. Some people have a longer than usual anagen growth period. These people may be able to grow more hair than the average person. However, others struggle to grow shoulder length hair. These people have a shorter than normal anagen period.
Your health can also affect hair growth. Poor nutrition can cause some hair follicles to stop growing or cause the hairs that grow to become weak or thin. Problems with hair growth can result from thyroid problems or other conditions like anemia, diabetes and lupus. Health experts say people who experience a sudden increase in hair loss should seek medical advice.
最新
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25