General anesthesia may cause short-term delirium, but the evidence isn’t clear on the long-term effects on the brain.

General anesthesia may be used routinely in surgeries, but it’s not without risks. Short-term side effects like sore throat and nausea are common, but several long-term side effects — like confusion and memory loss — have also been associated with anesthesia.

You won’t remember what happened to you while under anesthetic, but beyond that, some people feel their memory is slower to recover following a procedure where anesthesia was involved.

Some research suggests that some people may really develop memory problems, including dementia, following procedures that require anesthetic. But it’s not so clear-cut that the anesthetic is responsible for the changes in memory.

Keep reading to learn what the evidence says and what you should discuss with your doctor before going under for surgery.

Currently, anesthesia is still considered safe. However, occasionally, some research has suggested that anesthesia may increase a person’s risk of developing dementia or Alzheimer’s disease.

A 2022 study found that the incidence of dementia among surgical patients who had general anesthesia was higher than in people who had regional anesthesia.

During general anesthesia, you’re given medication that allows you to not feel or remember the procedure. In regional or local anesthesia, the medication temporarily numbs a small part of the body for surgery.

A 2015 study also found that general anesthesia seems to lead to increased levels of Alzheimer’s disease. People who had anesthesia had higher levels of clumps or proteins in brain cells that are associated with Alzheimer’s disease.

However, a 2020 study in older adults did not find an association between anesthesia and dementia, no matter the type used.

In a study of twins from 2016, researchers found no significant differences between twins who had previously had general anesthesia and the twins who did not.

Even in studies that find a connection between people who have had anesthesia and dementia or cognitive decline, they have not been able to prove that brain changes are directly a result of the anesthetic.

However, anesthesia may affect the brains of adults in other ways, especially older adults.

Immediately after waking up from anesthesia, it’s not uncommon for someone to experience confusion, even delirium. However, changes to the brain after anesthesia may be longer lasting than originally understood.

A 2021 study found that cognitive decline, including postoperative delirium and cognitive dysfunction, is quite common in patients over age 65.

In fact, that study found that 65% of patients over age 65 experienced postoperative delirium and 10% developed long-term cognitive decline.

Researchers in 2020 suggest that general anesthesia could prevent brain cells from properly repairing damage. Combined with the lower levels of oxygen and lower body temperature during surgery, the effect on brain cells could be long-term.

However, aging causes a number of changes in the brain, too. It’s unclear if anesthesia contributes to this by speeding up the changes or if surgery and anesthesia uniquely affect the brain’s important functions.

When possible, local or regional anesthesia may be a better option for adults with cognitive decline or dementia.

People with dementia are more likely to develop post-operative delirium. At the same time, delirium can increase the risk of other complications, such as falls, that will require prolonged hospitalization. These risks can be managed with a care team that is aware of the patient’s needs.

In some people, avoiding certain types of drugs before and after surgery may help reduce these risks, too. Intensive recovery therapy may be able to help people with dementia more successfully recover from surgery.

Feeling uncertain about an upcoming surgery is to be expected. Certainly, procedures can have side effects and risks, as can the anesthetic that may be necessary to perform the procedure.

Currently, there is not enough evidence to suggest that anesthesia increases your risk of dementia or Alzheimer’s disease. There may be some temporary cognitive changes — especially in older adults — but most people will not experience long-term issues.

Talk with a doctor or your surgeon about any concerns. Together, you can discuss what options are available to you and will work best for your procedure and health.

In some cases, local anesthesia may be an acceptable alternative.