Why am I losing my hair??

i'm only 18 and my hair has been falling out for two years i wasnt really that worried at first because it wasnt noticeable but i can actually see my scalp now :'( im only losing 50-100 hairs a day but new hair isnt growing back.?? i got my hormones checked (thyroid, estrogen, testostrone, etc) they were all normal. i think my iron levels are ok too..could i have an automimmune disorder?? doctors plz helpWhy am I losing my hair??
You may have Polycystic Ovary Syndrome, it is a very common health problem that affects teenage girls and young women. It is related to an imbalance in a girl's hormones. The ovaries produce higher than normal amounts of androgens, and this can interfere with egg development and release. Some of the eggs develop into cysts, which are little sacs filled with liquid. Instead of being released during ovulation, as an egg is during a normal menstrual cycle, the cysts build up in the ovaries and may become enlarged. Because girls with PCOS are not ovulating or releasing an egg each month, it's common for them to have irregular or missed periods.



Some signs includes; very heavy periods or periods that come more than once a month, weight gain, obesity, or difficulty maintaining a normal weight, especially when the extra weight is concentrated around the waist, a condition called hirsutism where a girl grows extra hair on her face, chest, abdomen, nipple area, or back (a little of this is normal for most girls, though), thinning hair on the head, acne and clogged pores,darkened, thickened skin around the neck, armpits, or breasts, and high blood pressure, high cholesterol, or diabetes mellitus.Why am I losing my hair??
Here is a trusted web site from Merck, they have a home edition also:



http://www.merck.com/mmpe/sec10/ch124/ch



common causes in women are birth control pills and stress.



Heavy metal, vitamin A poisoning, and syphilis should be considered. The merck article goes through about all the major causes.
Stress?
Is that the only symptom you have? Well, it can be stress, like other people said (I had a friend that lost a lot of hair because of stress). If you don't think is stress, you may want to be alert to any other symptom, anything from headaches to changes in your skin. I'm not a doctor, but giving these details to a doctor will make the search for your problem easier. Also, do you use any hair products? Some gels tend to weaken the hair and fall. Do you comb your hair too much, do you use hats?
It could be your stress level or any medications you may be on. You need more test done for a correct answer.