Minor side effects of general anesthesia include nausea and vomiting, sore throat, confusion, itching and chills, according to the American Society of Anesthesiologists. On rare occasions, serious side effects can occur, including heart attack or stroke, blood pressure problems, pneumonia, medication reactions and muscle damage, states WebMD.
Confusion or difficulty thinking clearly most often occurs as the patient wakes up from the anesthesia, explains the American Society of Anesthesiologists. Chills are also most common as the patient wakes up. A sore throat may occur if the patient had a breathing tube during the procedure. Itching occurs due to the narcotics often used as part of general anesthesia.
General anesthesia suppresses functioning in many of the body's systems, including the digestive, respiratory and circulatory systems, notes WebMD. Because it affects so much of the body, the potential side effects also affect different systems. The risk of side effects is greater with general anesthesia than with local or regional anesthesia because it affects the entire body.
The risk of serious side effects is small in patients who are otherwise healthy, says Mayo Clinic. Anesthesia is generally considered safe, even for sick patients. Patients face an increased risk of complications if they have existing health conditions such as smoking and heavy alcohol use, obstructive sleep apnea, high blood pressure, diabetes and medical problems related to the heart, lungs and kidneys.