Why cant I start my periods

havent started my regular periods for 4 years now. when I woz 17 I stopped my periods all together and now im 21 I still cant start my period...I weigh 16 stones and I get headaches and also im loosing hair...what is the common issue that I cant start...

my period...and what can I do to start my period again...does what I have got a name for it so I can tell my doctor and he can prescribe me some medication.

There are a few reasons to why girls stop their period. Some women who experience a loss of menstruation for a period of three months or more, may have amenorrhea. Amenorrhea has been classified as being either primary or secondary. Primary amenorhhea is typically diagnosed if you are over the age of 18 and have yet to start menstruating. Secondary amenorrhea takes place if you've previously had your period and then lost it.

Your periods could have stopped for many other reasons. It may have to do with your emotions. You may:
-live with a lot of stress
-be sad or depressed
-take medicine, which might affect your periods, for nervousness or depression.

You may have a problem with your glands. You may:
-have a tumor in the brain or an ovary or other glands
-have a cyst in an ovary
-have a problem with your thyroid
-make too much prolactin (a hormone).

You may have other health problems. You might:
-have a chronic illness
-have a brain injury
-have a problem with your uterus
-have had chemotherapy or radiation therapy.

And finally you may:
-not get enough to eat
-exercise every day for hours at a time
-have been or are a heavy smoker
-have lost or gained weight suddenly.

If none of the above pertains to you then try visiting your doctor.

Don't go to a message board for advice. Being that you are 21 and you're not having regular periods and the other problems you mentioned ... You should see a doctor asap.

If you haven't had your period in four years then you should go ask your doctor why.

u should ask a doc about that, but it soulds like maybe you have ovarian cancer?

some ovarian cancer symptoms:

nausea
loss of appetite
hair loss
mouth sores
an increased chance of infection (shortage of white blood cells)
bleeding or bruising after minor cuts
tiredness

well I think you got to talk to your doctor because im only 12 and I get my period regularly

I think you need to go to the doctor asap, but same for me as funadvise, and did you know that if you have three percent or less of body fat that you stop getting your period. it happened to anne frank a lot, but she was also eating extremely poorly

I might have figured something out. I was reading this article on soy, and this person ate a lot of soy, and if you eat a lot of soy this could be the problem

you cant just ask anyone this question you need to consult a doctor x