Here are some reasons for it..

1. Depression

2. Anemia

3. Rheumatoid Arthritis

4. Diabetes

5. Thyroid Disease

If you are having a sleeping problem I would go to your doctor and get it checked out. Don't just rely on sleeping pills and avoid maybe a serious problem. I think the reason why I don't sleep is because of stress and depression.

inthelight said: i think i get tired when im depressed. i stay up all night thinking about whats going on in my life. thoughts keep racing through my mind and its like i cant shut them off

I'm the exact same way. And when I fall asleep I'll wake up in the middle of the night and cry over it again and stay thinking about it.