General anesthesia can result in a variety of side effects that cause discomfort or impact recovery. For most individuals, these post-anesthesia side effects appear immediately after the procedure and last only a few hours. The most common immediate reactions include grogginess, confusion, and drowsiness, which typically last only a few hours as anesthesia wears off. Physical symptoms such as nausea and vomiting, affecting approximately one in three patients, generally resolve within a few hours, though some individuals may continue to feel sick for one to two days. Other common physical side effects like dry mouth, dizziness, and itching tend to be transient, frequently disappearing as the patient resumes normal hydration and the body continues processing the anesthetic agents.
Intubation may lead to a sore throat or hoarseness, which typically resolves after the first day. However, in rare instances of pharyngolaryngeal injury, these symptoms can persist for months. Muscle aches and shivering are also frequently reported side-effects, with shivering—the body’s response as it rewarms after surgery—lasting from a few minutes to several hours post-anesthesia. While these immediate effects are manageable and short-lived, certain complications, particularly those affecting cognitive function, can follow a more extended timeline. This is especially true for older adults or those with significant underlying health conditions, such as heart or lung disease.
One of the more significant side effects of anesthesia is postoperative delirium, a state of acute confusion and disorientation following a procedure. Most cases resolve within a week, though patients may face difficulties with certain normal tasks in the meantime. Beyond the first week, patients may experience what is known as delayed neurocognitive recovery, in which longer-term problems with memory or focus persist after surgery. For a subset of patients, these issues can transition into postoperative neurocognitive disorder, in which continued cognitive impairment lasts some duration between one to twelve months after surgery.
How long post-anesthesia side effects last is multifactorial, influenced by the patient’s age, the complexity and length of the surgery, and the presence of pre-existing conditions like diabetes or obesity. While the majority of side effects are mild and dissipate within hours, there is a small chance of more serious, longer term impacts. Patients are encouraged to follow all pre-surgical instructions and maintain open communication with their anesthesia providers and surgeons to minimize risks and ensure a clear understanding of what to expect during their recovery journey.
References
Kong H, et al. Perioperative neurocognitive disorders: A narrative review focusing on diagnosis, prevention, and treatment. DOI: 10.1111/cns.13873
Amirshahi M, et al. Prevalence of postoperative nausea and vomiting: A systematic review and meta-analysis. DOI: 10.4103/sja.SJA_401_19
Healthline. Side Effects of General Anesthesia: What to Expect. https://www.healthline.com/health/side-effects-of-general-anesthesia
Anesthesia Patient Safety Foundation. What are the Side Effects of Anesthesia? https://www.apsf.org/patient-guide/what-are-the-side-effects-of-anesthesia/
Rauch S, et al. Perioperative Hypothermia—A Narrative Review. DOI: 10.3390/ijerph18168749
Bekele Z, et al. Incidence and risk factors for postoperative sore throat after general anesthesia with endotracheal intubation: prospective cohort study. DOI: 10.1097/MS9.0000000000000786