I am student of university sometimes when i begin studying i become so sleepy and dizzy can not study?

See your doctor: Most students don't get enough sleep, eat right, and exercise. But before we can diagnose this problem, you need a physician to examine you to rule out mono or other treatable illness. Eye strain can cause this, as well as anxiety, hypoglycemia, fibromyalgia, stress, et al. Start getting on a schedule for sleeping 8'hrs, eating regular meals with lots of vegetables,and water. No,alcohol.