A full head of thick, lustrous hair attracts attention. Stores shelves are packed with products promising rapid hair growth. Unfortunately, hair growth is fairly consistent. Growth varies according to the body area and with age, but in general, all hair grows at about six inches in a year.
Hair Structure
Hair consists of three parts: the outer cuticle, made up of overlapping cells; the cortex, which contains tightly packed cells; and, in longer hairs, the medulla, a layer of loosely packed, large cells separated by air pockets, says The Trichological Society. The cuticle contains keratin, a flexible protein. Each hair grows from a follicle, essentially a slender indentation in the skin. Hair cells die once the hair shaft emerges from the skin.
Growth Phases
The hair growth cycle begins with the anagen phase. Hair actively grows during this phase, which lasts from two to seven years, according to The Trichological Society. The hair follicle then enters the catagen phase, a short period lasting approximately two weeks. The follicle stops producing new cells, the hair shaft narrows and the hair may lose color. During telogen, the final phase, the follicle rests for approximately four months. The hair shaft then loosens and sheds, beginning a new anagen cycle.
Typical Growth Rates
Scalp hair grows faster than hair on other areas of the body, such as the arms, according to Keratin.com. Hair grows faster for women than men, and the growth rate varies according to age. On average, scalp hair grows a half-inch per month. Hair grows faster in prepubescent children, at an average rate of 0.41 mm per day. During adolescence and young adulthood, growth slows to approximately 0.30 mm daily, and then increases to 0.34 mm daily in mature adults. Hair growth slows for older adults to an average rate of 0.32 mm per day, according to Keratin.com.
Normal Shedding
A small amount of hair loss is normal, advises the American Academy of Dermatology (AAD). The follicles must shed the old hair to make room for new shafts. Losing up to 100 hairs daily is normal and healthy, says the AAD.
Stimulating Growth
No lotions, pills or massages will make hair grow faster, according to Hair News. Regular shampooing and conditioning with quality products and a daily multivitamin can, however, improve overall hair health. The exception is the hormone surge experienced during pregnancy, which temporarily stimulates hair growth. Certain factors may reduce hair health and slow growth. Illness, unhealthy diet, poor hair care, medications, extreme stress or a genetic predisposition to pattern baldness all may affect hair health and slow growth, says Hair News.
Member Comments