Although some people may worry that anesthesia could worsen their multiple sclerosis (MS) symptoms or bring on a relapse, there is no evidence to suggest that this is true.

According to the National Multiple Sclerosis Society (NMSS), the risks of surgery and anesthesia are the same for people with MS and people without MS. However, other aspects of surgery, such as the recovery process, may be more challenging for those with symptoms such as muscle weakness.

In this article, we look at whether anesthesia is safe for people with MS, the impact of local and general anesthesia, anesthesia and MS medications, and other ways surgery may impact MS.

A person with MS waiting on an operating table for anesthesia, which a doctor is about to administer via a mask.Share on Pinterest
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All anesthesia carries a small amount of risk, but there is no indication that it affects people with MS more than people without the condition.

The only exception to this are people with advanced MS who experience respiratory problems. They may have an increased risk of anesthesia-related complications. This accounts for a small percentage of those with MS.

Research has not found any connection between anesthesia and MS relapses or symptom exacerbations. A 2019 study of 281 people found that neither surgery nor anesthesia increased the risk of relapse after an operation.

A 2020 review suggests that anesthesia may actually reduce the symptoms of MS. However, the author of the review cautions against using spinal anesthesia, as this delivers a high dose of the drug to the central nervous system and areas of the brain affected by MS lesions.

Local anesthesia reduces sensation in a specific part of the body. It works by acting on particular neural pathways to stop the nerves at the site of a procedure from sending pain signals to the brain. It usually takes just a few minutes for the anesthesia to take effect, and it wears off within a few hours.

Local anesthesia is safe for minor procedures and rarely causes serious side effects. A person may feel some pain and tingling as the doctor administers the anesthesia, but the pain is usually mild. Other temporary symptoms may include:

  • numbness, tingling, or weakness
  • headaches
  • muscle twitching
  • blurry vision

In rare cases, more serious side effects may include:

  • a severe allergic reaction
  • seizures
  • cardiac arrest

In a review article on MS and regional anesthesia, which affects larger areas than local anesthesia, the researcher concluded that patients with MS do not need to avoid anesthesia.

General anesthesia refers to medication that puts a person into a controlled, sleep-like state of unconsciousness. This reduces their awareness and sensation during a procedure.

General anesthesia takes effect quickly. A person may feel lightheaded before they become unconscious. The most common side effects are usually very short-term, and include:

  • nausea and vomiting
  • feeling cold and shivering
  • dizziness
  • trouble passing urine
  • memory loss and confusion

There is a very small risk of complications, such as a severe allergic reaction or waking up during the operation. Very rarely, general anesthesia causes complications that result in death. This risk does not appear to be any higher for people with MS.

Certain medications used to treat MS symptoms may interact with anesthesia. A person should discuss any and all medications they are taking with their doctor before surgery. The doctor will be able to make recommendations on a case-by-case basis.

While anesthesia is not associated with higher risk of side effects or complications in most people with MS, it does present other challenges. It may cause:


With any surgery, there is a risk of infection. Infection or fever may exacerbate MS symptoms. However, this risk is generally low, and doctors can treat infections with antibiotics.


There is no evidence that stress caused by surgery can cause an MS relapse. Evidence on the connection between stress, trauma, and MS symptoms is mixed, according to the United Kingdom charity Multiple Sclerosis Trust.

However, some people feel that stress has a relationship with their symptoms, and experiencing stressful events may make MS feel harder to cope with. Having the right support and a plan for a peaceful recovery may help.

People may need to arrange:

  • time off work
  • transport to and from hospital
  • a travel bag containing everything they will need
  • a comfortable place to recover when they leave the hospital

Depending on the surgery, people may also need assistance with everyday tasks while they recover.

Longer recovery process

People with MS-related muscle weakness or fatigue may find it more difficult to recover after surgery if they have to spend a prolonged period in bed, as these symptoms make it harder to regain strength afterwards.

Physical therapy can help with this. The NMSS suggests starting physical therapy as soon as someone is able to with a doctor’s recommendation.

In most cases, anesthesia is safe for people with MS and appears to have the same level of risk as it does for people without MS. However, other aspects of undergoing surgery, such as recovery, may be more difficult, depending on a person’s symptoms.

People with severe MS symptoms, respiratory difficulties, or who take medications should discuss these factors with their doctor so they can get personalized advice.