Anesthesia affects receptors in the brain, which may cause side effects following surgery. However, evidence that anesthesia causes long-term memory loss is inconclusive.

Some people may experience short-term memory loss after having surgery under general anesthesia. Further research is needed on whether this memory loss can be more long-term and whether anesthesia can increase the risk for dementia.

This article explores how anesthesia affects the brain and impacts memory. It examines the evidence that general anesthesia is linked to dementia and discusses other side effects.

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Anesthetics act on the brain mainly by modulatingTrusted Source target receptors that control neurons. Scientists have studied the effects of general anesthetics after they wear off and if this impacts someone’s memory.

A 2020 studyTrusted Source on 400 patients with an average age of 50 revealed that short-term memory (24 hours after surgery) was significantly decreased after general anesthesia.

Older animal studies suggest that general anesthesia impacts γ-aminobutyric acid type A receptors (GABAARs) in the brain, and their activity continues after the anesthetic drug is gone from the body, causing persistent memory deficits.

Experts previously thought that delirium and postoperative cognitive dysfunction (POCD) after surgery were separate entities. However, according to a 2021 reviewTrusted Source of recent studies, they may be linked. The review notes that some patients may be more vulnerable to cognitive decline after the stressors of surgery and anesthesia.

The researchers suggest that inflammation in the brain due to stress during surgery, vascular disorders, and previously undiagnosed neurodegenerative disorders may be risk factors for POCD.

A review in the British Journal of Anaesthesia noted the challenges in drawing any firm conclusions about POCD and dementia due to a lack of agreed definitions and consistency of testing in clinical studies.

The review notes that 10% of older adults have a persistent degree of cognitive decline up to 3 months after a surgical procedure. It suggests that older adults who receive general anesthesia may be more at risk of dementia, but more studies are needed to confirm this. However, there is no established guideline for what type of anesthesia is best in order to prevent POCD.

Another 2023 population-based studyTrusted Source looked at the route of anesthesia and how it affects the risk of dementia. They found that the incidence of dementia was higher among people with general anesthesia than those undergoing regional or local anesthesia.

Regional anesthesia affects the whole nerve root or is injected in or near the spine. Local anesthesia is injected just into the skin.

Additionally, delivering general anesthesia by inhalation was linked with a higher incidence of dementia than non-inhalation methods. However, the authors note that scientists must conduct large-quality trials to confirm these findings.

Conversely, however, a large observational studyTrusted Source of older adults who had surgery with over 4 years of follow-up found no difference between general and regional anesthesia and the development of dementia.

If a person has concerns due to already experiencing early signs of dementia or having a family history of dementia, they can speak with their healthcare professional about the risks and benefits of optional surgical procedures.

The following are some common side effects of general anesthesia:

Additionally, older adults who may have poorer health and undergoing lengthy surgical procedures may be at risk of the following complications of general anesthesia:

Death due to general anesthetic is rare and occurs in approximately 1 in 150,000Trusted Source people.

The following are some questions people frequently ask about anesthesia.

Does anesthesia affect cognitive ability?

Some people may experienceTrusted Source delirium or short-term memory issues after general anesthesia. Some studies suggest that older people may be at risk of longer-term cognitive problems.

How long does it take for your brain to recover from anesthesia?

Common short-term side effectsTrusted Source of anesthesia are confusion or memory. Experts advise that recovering from these effects may take 1–2 days.

Where does anesthesia affect the brain?

Research indicatesTrusted Source that general anesthetics have a global effect on the brain, affecting protein receptors in the lipid membrane. These receptors cause neurons to relay information to each other, affecting long-range connections in the brain and nervous system.

Anesthetics affect target receptors in the brain and may have side effects. Delirium and memory loss are common short-term complications of general anesthesia, and some evidence suggests that longer-term memory loss may occur in some people.

However, more research is needed in order to confirm these initial findings. People who are concerned about the side effects of anesthesia should speak with their surgeon or anesthetist.