Is it normal, not sleeping for long periods of time?
There are many reasons why someone might not be able to sleep. The three main causes of sleep deprivation (insomnia) are stress, diet, and a lack of exercise. You should definitely try to de-stress, eat lots of healthy foods (no less than 3 hours before bed), and exercise 4 times a week.
If you cannot decrease stress in your life, try picking up yoga, meditation, or drinking one or two glasses of wine per night. Other alternative medicine possibilities include EFT and other herbal sleep supplements.