How risky is ischemia?

Depends: It depends on how severe it is and which organ is ischemic. For instance it would be more serious to have ischemia to the heart or brain than to your foot.

Depends on: The severity of the ischemia, and also the cause. Ischemia from an obstruction is more dangerous than ischemia from vasospastic disease. You really need to discuss this with your doctor.

Definition: ischemia: The term ischemia generally suggests a reduction of the blood supply to a given area of the body such that the functionality of that part of the body is impaired. Could be from a blockage in an artery delivering blood to that part of the body, or could be from a general reduction in blood supply to deliver to that part of the body. Could cause heart attack, stroke, so could be risky, yes.