Effects of Anesthesia

If you’re having surgery, you most likely will have some type of anesthesia to keep you from feeling pain during the procedure. While anesthesia is very safe, it can cause side effects both during and after the procedure. Most side effects of anesthesia are minor and temporary, though there are some more serious effects to be aware of and prepare for in advance.

How can you lower your risk of side effects?

The most important thing you can do to prevent anesthesia side effects is make sure an anesthesiologist is involved in your care. An anesthesiologist is a medical doctor who specializes in anesthesia, pain management, and critical care medicine.

The most important thing you can do to prevent anesthesia side effects is make sure an anesthesiologist is involved in your care.

Before your surgery, meet with the anesthesiologist to discuss your medical history, health habits, and lifestyle. This information will help the anesthesiologist know how you might react to anesthesia and take steps to lower your risk of side effects. This meeting is also a good time for you to ask questions and learn what to expect.

Cropped shot of a doctor talking to a senior patient in a clinic

What are the types of anesthesia and their side effects?

There are four main types of anesthesia used during medical procedures and surgery, and the potential risks vary with each. The types of anesthesia include the following:

General anesthesia. General anesthesia causes you to lose consciousness. This type of anesthesia, while very safe, is the type most likely to cause side effects. If you’re having general anesthesia, an anesthesiologist should monitor you during and after your procedure to address any side effects and watch for the possibility of more serious complications.

Side effects of general anesthesia can include:

  • Nausea and vomiting – This very common side effect can occur within the first few hours or days after surgery and can be triggered by a number of factors, such as the medication, motion, and the type of surgery.
  • Sore throat – The tube that is placed in your throat to help you breathe while you’re unconscious can leave you with a sore throat after it’s removed.
  • Postoperative delirium – Confusion when regaining consciousness after surgery is common, but for some people — particularly older patients — the confusion can come and go for about a week. You may feel disoriented and have problems remembering or focusing. This can worsen if you are staying in the hospital for a few days after the procedure, especially in intensive care, because you are in an unfamiliar place. Having a loved one with you helps, along with doing some other simple things: wearing your glasses or hearing aids as soon as you can after the procedure and making sure you have family photos, familiar objects, and a clock and calendar in your room.
  • Muscle aches – The medications used to relax your muscles so a breathing tube can be inserted can cause soreness.
  • Itching – This is a common side effect of narcotics, one type of pain medication sometimes used with general anesthesia.
  • Chills and shivering (hypothermia) – This occurs in up to half of patients as they regain consciousness after surgery, and it might be related to body temperature.

Rarely, general anesthesia can cause more serious complications, including:

  • Postoperative delirium or cognitive dysfunction – In some cases, confusion and memory loss can last longer than a few hours or days. A condition called postoperative cognitive dysfunction can result in long-term memory and learning problems in certain patients. It’s more common in older people and those who have conditions such as heart disease (especially congestive heart failure), Parkinson’s disease, or Alzheimer’s disease. People who have had a stroke in the past are also more at risk. It’s important to tell the anesthesiologist if you have any of these conditions.
  • Malignant hyperthermia – Some people inherit this serious, potentially deadly reaction to anesthesia that can occur during surgery, causing a quick fever and muscle contractions. If you or a family member has ever had heat stroke or suffered from malignant hyperthermia during a previous surgery, be sure to tell the anesthesiologist.

Close up of IV bag with patient in bed in the background.

Monitored anesthesia care or IV sedation. For some procedures, you may receive medication that makes you sleepy and keeps you from feeling pain. There are different levels of sedation — some patients are drowsy, but they are awake and can talk; others fall asleep and don’t remember the procedure. Potential side effects of sedation, although there are fewer than with general anesthesia, include headache, nausea, and drowsiness. These side effects usually go away quickly. Because levels of sedation vary, it’s important to be monitored during surgery to make sure you don’t experience complications.

  • Headache – This can occur a few days after the procedure if some spinal fluid leaks out when regional anesthetic is delivered through the spine, as in an epidural or spinal block for childbirth.
  • Minor back pain – Soreness can happen at the site where the needle was inserted into the back.
  • Difficulty urinating – If you were numbed from the waist down, it may be difficult to urinate for a little while after the procedure.
  • Hematoma – Bleeding beneath the skin can occur where the anesthesia was injected.

More serious but rare complications include:

  • Pneumothorax – When anesthesia is injected near the lungs, the needle may accidentally enter the lung. This could cause the lung to collapse and require a chest tube to be inserted to re-inflate the lung.
  • Nerve damage – Although very rare, nerve damage can occur, causing temporary or permanent pain.

Local anesthesia. This is the type of anesthesia least likely to cause side effects, and any side effects that do occur are usually minor. Also called local anesthetic, this is usually a one-time injection of a medication that numbs just a small part of your body where you’re having a procedure such as a skin biopsy. You may be sore or experience itching where the medication was injected. If you’ve had this type of reaction to local anesthesia in the past, be sure to tell your physician. You may be given a different type of anesthetic or a medication to counteract the side effects.

Regional anesthesia. Regional anesthesia is a type of pain management for surgery that numbs a large part of the body, such as from the waist down. The medication is delivered through an injection or small tube called a catheter and is used when a simple injection of local anesthetic is not enough, and when it’s better for the patient to be awake.

This type of anesthesia, including spinal blocks and epidurals, is often used for childbirth. In fact, an epidural is the most common type of pain control used for labor and delivery. It allows the mother to be awake and able to push when it’s time to deliver the baby, but numbs the pain. Another type of regional anesthesia — a spinal block — is stronger and is used during procedures such as cesarean deliveries, also known as C-sections. Spinal blocks and epidurals allow the doctor to surgically deliver the baby without causing pain to the mother, and without subjecting the baby to sedating drugs that might be harmful.

Regional anesthesia is very safe and doesn’t involve the potential complications and side effects that can happen with sedation and general anesthesia. But it does carry some risks, and it’s important that it be provided and monitored by an anesthesiologist.



Female nurse looking at child patient.

Anesthesiologists work with your surgical team to evaluate, monitor, and supervise your care before, during, and after surgery—delivering anesthesia, leading the Anesthesia Care Team, and ensuring your optimal safety.