Anesthesia is a very common and safe medical procedure that prevents you from feeling pain during medical interventions, such as surgery, certain diagnostic tests, and dental work.
It works by preventing your nerves from passing signals to the brain, causing numbness in a specific area of the body — from a small area to a whole region of your body — or inducing a controlled state of unconsciousness.
Depending on the type and dose of anesthesia used, you may remain awake and alert, feel drowsy, or be completely unconscious.
There are several types of anesthesia, which are used for different purposes and have different effects on the body.
Local Anesthesia
Local anesthesia causes numbness in and around a small, specific area of the body where the anesthetic medicine — typically lidocaine — is applied.
Unlike other forms of anesthesia, local anesthesia can be performed by any medical professional and does not require specialized training. It’s commonly used for minor procedures, such as to block pain from a tooth during dental work or an area of skin that requires stitches.
During local anesthesia, you remain fully awake and alert, and while you may not feel pain in the affected area, you may feel pressure.
Regional Anesthesia
Administered by an anesthetist, regional anesthesia blocks pain in a larger region of the body, such as an arm, leg, or the entire lower half of the body. It targets larger nerves that transmit signals across an entire area of the body.
Hand surgery, for example, requires regional anesthesia, given as a shot of numbing agent near the nerves in the armpit, causing your whole arm to go numb. Epidurals during childbirth are another common example.
Unless you also receive a sedative, regional anesthesia with medications like lidocaine, bupivacaine, or ropivacaine alone will not cause you to sleep.
Monitored Sedation
Sedation, sometimes known as monitored anesthesia care and twilight sedation, relaxes the body, reduces anxiety, and induces sleepiness. The level of sedation you experience depends on the procedure and how you respond to the medications, which include midazolam, propofol, and ketamine.
Minimal sedation relaxes you while leaving you awake and able to respond to questions or instructions.
Moderate sedation will make you sleepy, but you can be awakened easily and interact with your healthcare team, though you may not remember any of it.
Deep sedation will give you a nice nap (you won’t be completely unconscious but you won’t be able to remember it, either); while you can breathe on your own, you will need close monitoring and may need to be given oxygen because the medications can cause your breathing to become slower or shallower.
Sedation is often combined with local or regional anesthesia for pain control and is useful for colonoscopies and complex dental procedures like wisdom teeth removal.
General Anesthesia
Used for major, invasive surgeries — such as those that are time-consuming like back surgery or involve internal organs — general anesthesia is likely what you imagine when you hear the word “anesthesia.” It affects your entire body, making you unconscious and preventing you from feeling pain or even moving.
Many body functions will slow down during general anesthesia and may need help to work effectively — for instance, you won’t be able to breathe on your own and will require a ventilator to breathe for you. General anesthesia requires the same medications as sedation, just in higher doses, and you will remain asleep while the drugs are in your system.
Anesthesia allows healthcare providers to perform surgeries and other treatments safely and efficiently while keeping you comfortable and free from distress. It’s used to eliminate pain and discomfort during a wide range of medical procedures, including:
Stitches
Dental procedures including tooth removal and root canals
Eye surgery
Biopsies (removal of tissue for examination under a microscope)
Trained anesthesiologists or nurse anesthetists administer most types of anesthesia. Before your procedure, they will discuss with you your anesthesia options, their various risks, and anything else you may need to know about the experience and pain management.
Depending on your procedure and preferences, your healthcare provider will administer a local anesthetic via:
Topical lotion or spray
Skin patch
Eye drop
Oral rinse
Injection with a needle and syringe
Anesthesia specialists administer regional anesthesia by injection, with the location depending on what area of the body requires numbing.
They administer sedation and general anesthesia intravenously or as an inhaled gas (through a mask covering the mouth and nose).
Local anesthesia doesn’t require any special preparation. For other types of anesthesia, your healthcare provider or anesthesiologist will provide specific instructions.
Before your procedure, your healthcare provider or anesthesiologist will discuss the procedure with you, at which point you should let them know about:
Your allergies, particularly any allergic reactions you have had to anesthesia (including local) in the past
Herbal supplements you take, which may affect your heart rate and blood pressure
Your medications, including birth control or erectile dysfunction drugs like sildenafil (Viagra)
Your smoking and drinking (alcohol) habits
If you are breastfeeding, pregnant, or might be pregnant
Your use of street drugs, including marijuana, cocaine, amphetamines, or others (keep in mind this is private information between you and your providers)
Some general guidelines to follow before your procedure include:
Stop smoking one week before your procedure.
Stop taking herbal supplements one to two weeks before.
Stop taking certain medications, as instructed.
Stop eating solid foods and drinking liquids as directed, typically eight hours and two hours before arrival at the medical facility, respectively.
Stop using cannabis at least two hours before your procedure and possibly longer, as advised by your anesthesiologist.
Arrange for someone to bring you home after your procedure, as you won’t be allowed to drive yourself home or use a taxi or ride share service if you’ve had any kind of sedation.
Wear loose, comfortable clothing.
During anesthesia, your anesthesia care provider will closely monitor your vital signs, watching for any changes in your body functions, such as:
Heart rate and rhythm
Blood pressure
Body temperature
Oxygen levels
Breathing
They will also manage any fluid and blood replacement you may need and may monitor brain activity for some procedures.
If you’re under general anesthesia, you will be in a deep sleep and you won’t feel or remember anything. Anesthesia awareness — waking up during surgery — occurs in only 1 or 2 of every 1,000 procedures involving general anesthesia, according to the American Society of Anesthesiologists. Even if you do become conscious, you likely will not feel anything.
With local or regional anesthesia, you will be awake but free of pain (you may still feel pressure during your procedure). If you are sedated, you’ll feel relaxed and drowsy and may fall asleep.
Anesthesia is generally safe, but like any medical procedure, it carries some risks. During anesthesia, you may experience:
Allergic reactions to anesthetic drugs
Anesthesia awareness
Malignant hypothermia, a reaction to anesthesia that causes a quick fever and muscle contractions
Anesthesia is riskier for you if you have or have had:
Diabetes
Heart disease
High blood pressure
Kidney problems
Lung conditions
Obesity
Sleep apnea
Stroke
Seizures
A history of smoking or drinking two or more alcoholic beverages a day
Recovery time varies depending on the type of anesthesia used.
If you have local anesthesia, you won’t need time to recover and can go home as soon as you feel well enough. Similar is true for regional anesthesia, though you may experience headaches as you recover.
With general anesthesia, you will likely recover within a few hours, but you may experience pain as the anesthesia wears off, depending on the type of procedure you had. You may also continue to be sleepy and have impaired judgement and reflexes during recovery — it’s best to have someone with you for at least the first 24 hours after general anesthesia.
Recovery from sedation is similar to general anesthesia, but the effects wear off quicker.
Side effects from anesthesia depend on the type, with general anesthesia the most likely to cause side effects post procedure. These include:
Nausea and vomiting
Sore throat
Confusion, particularly with older patients
Muscle aches
Itching
Chills and shivering
In rare cases, general anesthesia can cause a serious complication called postoperative cognitive dysfunction — long-term memory and learning problems. You are more at risk of this complication if you:
Are older in age
Have heart disease, Parkinson’s disease, or Alzheimer’s disease
Previously had a stroke
Side effects from sedation include:
Headache, which may occur a few days after the procedure
Nausea
Drowsiness
Minor back pain
Difficulty urinating
Hematoma, or bleeding beneath the skin at the injection site
Sedation can also cause serious but rare complications including nerve damage and pneumothorax, or lung collapse (if anesthesia was injected near the lungs and the needle accidentally punctured the organ).
Local and regional anesthesia cause minor side effects, if any, which are typically localized to the injection site, such as itching, infection, and bleeding.
Rarely, regional anesthesia can cause headache, backache, and low blood pressure and heart rate. Local anesthetic toxicity (when you receive too much injected anesthesia) is a rare complication for both local and regional anesthesia — it causes confusion, slowed heartbeat, trouble breathing, and seizures.
Anesthesia is a vital part of modern medicine that allows for pain-free and safe medical interventions.
While it comes with some risks and side effects, especially with general anesthesia, it is considered a very safe procedure.
By understanding what to expect and following guidelines provided to you, you can approach your procedure with confidence and peace of mind.
