Waking with a painful erection. This understudied problem may occur more often than is reported, and can result in serious pain and loss of sleep. Daytime erections are not painful for men who have this problem. That’s because sleep erections and waking erections are governed by different parts of the brain, and it appears that painful sleep erections may be the result of spasms or ischemia. Oral baclofen currently appears to be the experimental treatment of choice, but that may change when more is learned about SRPEs.