M.D. Being over 50 and having sudden need to fall asleep during the day puts you at increased risk for a heart attack and early death.
Daytime sleepiness is associated with both inability to fall asleep and stay asleep at night.
It is associated with obesity, lung and heart disease and sleep apnea in which you stop breathing for more than 20 seconds many times during the night. If you have day-time sleepiness, check with your doctor. You may need an electrocardiogram and a check of your heart, and you lungs and nose for obstruction. You may also need to spend a night in a sleep chamber to see if you have sleep apnea. If you are overweight or have high blood pressure or high cholesterol, get on a program to lose weight, start a supervised exercise program and a diet, and perhaps drugs, to lower cholesterol.