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Anesthesiology is a branch of medicine that uses intravenous medicines to put you in a state of unconsciousness for surgery. These medications are called “anesthetics.”

There are three types of anesthesia: general, local, and regional. General anesthesia is the most potent form of anesthesia and typically puts the patient in a state of sedation.
Anesthesia is a medical necessity but also has some associated side effects ranging from mild to severe. (1)(2)
Read on to take a deeper look at them.
What Are the Possible Side Effects of Anesthesia?
Here are some common side effects of general anesthetics. (3)
1. Nausea and vomiting after surgery
Feeling sick or nauseous after surgery (also called postoperative nausea and vomiting) is a common side effect of general anesthesia. The most common anesthetic responsible for it is morphine.
Your doctor may prescribe some medicines such as antiemetics to help reduce nausea and vomiting. (4)
2. Shivering (hypothermia) and dizziness
Shivering is common among patients who wake up after receiving general anesthesia. It occurs due to a drop in body temperature after surgery. (5)
Your doctor may prescribe some medicine to help reduce the shivering.
3. Sore throat or hoarseness
Sore throat or hoarseness may occur after surgery under general anesthesia. It usually happens when a tube is inserted into your throat to help you breathe during the surgery.
Your doctor may prescribe some anti-inflammatory medicines to help treat it. (6)
4. Tooth damage
Tooth damage or cuts to the lips or tongue may occur when a tube is inserted into your throat during general anesthesia. Tooth damage is rare but can happen at times. It may be possible to prevent it by using mouthguards. (7)
5. Hypothermia
Hypothermia, or a drop in basal body temperature, is another unpreventable side effect of anesthesia. Doctors usually take special measures to prevent it from happening during surgery, but many patients go through it after the procedure. (8)
6. Impaired coordination or judgment
General anesthetics may make you feel drowsy or uncoordinated due to their potent effects on the central nervous system. It is advisable to rest for at least 2–3 days after surgery.
7. Postoperative delirium
Confusion or delirium is another side effect of general anesthesia. Older patients usually feel more severe effects of it and may need to rest and be taken care of 1–2 weeks after surgery.
8. Muscle aches
Some surgeries under general anesthesia require a breathing tube to be inserted via your throat. You may be given a muscle relaxant medicine for this purpose. This is a common cause of muscle aches afterward.
9. Itching
Narcotics are painkiller medicines sometimes used with anesthetics. They may cause itching and skin irritation.
10. Difficulty urinating or constipation
Surgeries on the lower half of the body may require the doctors to numb the area. This can cause difficulty in bowel movements or urination for a while after the surgery. The effects should resolve by themselves.
11. Others
More serious but rare complications include:
- Pneumothorax – This is a rare side effect that occurs when the needle of the anesthetic injection accidentally pierces the lung. This can cause the lung to collapse or deflate and may require emergency treatment from a pulmonologist. (9)
- Nerve damage – Very rarely, severe or permanent nerve damage may occur as a result of general anesthesia. (10)
During Surgery
The general anesthetic will be injected into your body or via a gas mask by your doctor. A trained anesthetist will be monitoring your vitals (breathing, blood pressure, etc.) during the surgery. (11)
After Surgery
After you wake up from surgery, you may feel groggy or disoriented for a while. The doctors may keep you under observation in postoperative wards for the required amount of time.
You may be discharged and allowed to go home once your medical staff gives the all-clear.
Preventing the Side Effects of General Anesthesia
Your doctor should take all possible measures to make sure you are safe during and after the surgery. The best way to prevent any harmful side effects of anesthesia is to make sure a certified anesthesiologist (a physician trained in anesthesia) is overseeing the surgery.
Meet your anesthesiologist a couple of days before the surgery and discuss your medical history, any tests you need to undergo, and risk factors with them. It is important to mention here that some people are at higher risk of anesthesia-related complications.
Smokers, overweight people, those with heart disease, and drug addicts may need special accommodations for the surgery. Do not hide these facts from your doctor, and inform them of any drugs or medications you are on.
Your anesthesiologist may ask you to stop smoking for a while before the surgery.
Complications and Risks Involved With Anesthesia
Here are a few risks associated with general anesthesia:
- A serious allergic reaction (anaphylaxis) (12)
- Breathing difficulties due to an allergic reaction
- Waking up mid-surgery (this is a very rare occurrence)
- Very rarely, anesthesia may prove to be fatal for some people. Doctors take all necessary measures to prevent this from happening.
Most-Asked Questions About Anesthesia
How is general anesthesia administered?
General anesthesia is usually given intravenously by a health care professional. It may also be given in the form of inhalation for young kids.
How long does it take for anesthesia to kick in?
It takes 30 seconds for anesthesia to work.
How long does anesthesia last?
There are different types of anesthesia and anesthetic drugs, and their effects may last from 8 hours to 5 days.
Final Word
General anesthesia may cause some side effects in most people but it is a necessary procedure for surgery. Serious complications of anesthesia are rare but not unheard of, and your medical history and screenings are taken properly by your doctor before administering it.
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