What causes excessive sweating with a small amount of exertion? night sweats? my heart has been checked out?

Warm air: If the ambient temperature is higher, you will sweat more. Try reducing the room temperature where you exercise and sleep. Have a healthy diet, exercise 30 minutes/day, drink plenty of water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. For nutrition: http://www.choosemyplate.gov/. Wish you good health!