What are the side effects of excess of sleep?

Check with your Dr.: Too much sleep, in itself and if done reasonably, may not be a problem. But the reasons for too much sleep may be signs of some underlying illness. I would check with your dr. You may need a sleep study.

HMMM: I think that the question may actually be..."what is causing excessive sleepiness. ?" this , may be a symptom of something else. I think it would be wise to see your family doc for a good history and physical exam and possibly a sleep study...