How hair grows.
Do you know you were born with about 5 million hairs on your body and about 100,000 hairs on your scalp? Hair is found on the scalp in what are called follicles which usually contain 1 to 4 hairs. We average about 2.2 hairs per follicle. Hair will grow and fall out and regrow many times during some ones lifetime. The hair growth cycle includes a growth phase (anagen), a phase in which it prepares to fall out (catagen), and the resting phase (telogen). Anagen can last years. Catagen is only a few weeks. Telogen lasts months and is a resting phase while the follicle is getting ready to produce a new hair. One question patients often ask is why their hair doesn’t start to grow immediately after a transplant. The answer is that most transplanted follicles go into the resting phase after the transplant process and will start to grow a new hair on average in about 4 months.
What causes hair loss?
Everyone loses some hair every day. Losing up to 100 hairs a day is normal.
But if hair loss runs in your family, you could lose a lot more hair. With this kind of hair loss, you may end up with bald spots if you are a man. If you are a woman, you may find that the hair on the top of your head is slowly thinning. About half of all people have this type of hair loss by around age 50.
Although hair loss is fairly common, it can be a tough thing to live with, especially when it changes how you look. But there are ways you can treat your hair loss.
Common causes of hair loss include:
- Family history. In most cases, hair loss is inherited, which means it’s passed down from one or both of your parents. This is called male-pattern or female-pattern hair loss.
- Stress, including physical stress from surgery, illness, or high fever.
- Chemotherapy, which is powerful medicine that destroys cancer cells.
- Damage to your hair from pulling it back too tightly, wearing tight braids or ponytails, or using curling irons or dyes.
- Age. You grow less hair as you get older. Hair also gets thinner and tends to break more easily as you age.
- Poor diet, especially not getting enough protein or iron.
- Thyroid diseases, such as hypothyroidism and hyperthyroidism.
- Ringworm of the scalp, which is common in children.
- Your symptoms will depend on what kind of hair loss you have.
If your hair is thinning, it happens slowly over time, so you may not notice the hairs falling out. If your hair is shedding, then clumps of hair fall out. You may lose hair all over your scalp, which is called general hair loss. Or you may lose hair only in one area, which is called focal hair loss.
Since your hair has a lot to do with your appearance, losing it may cause you to have lower self-esteem if you don’t like how you look. This is especially true in women and teens.
Your doctor will ask you some questions, like how much hair you’re losing, when it started, and whether your parents have hair loss. He or she will look closely at your scalp and hair loss pattern and may gently pull out a few hairs for tests.