Both Bell’s palsy and stroke can cause facial weakness, but stroke causes more widespread symptoms. Treatment may help Bell’s palsy resolve more quickly, but stroke requires immediate treatment.

Bell’s palsy and stroke are two nervous system conditions that can cause your face to droop on one side.

While Bell’s palsy may need treatment, it isn’t a medical emergency. But a stroke is a life threatening condition that requires fast treatment.

Here’s how to tell the difference between the two.

Bell’s palsy causes the muscles that control one side of your face to suddenly stop working, triggering temporary paralysis. This can make one of your eyebrows droop or sag.

This condition can cause you to have trouble making facial expressions and closing one eye. You may also drool from one side of your mouth.

Other common symptoms of Bell’s palsy include:

  • pain in your face or jaw or behind your ear
  • unusual facial sensations
  • increased or decreased tear production
  • changes in taste
  • sensitivity to noise
  • difficulty eating or drinking

In both stroke and Bell’s palsy, one side of your face might feel weak, numb, or paralyzed. But during a stroke, you might also experience one-sided weakness in the rest of your body, such as in your arm or leg.

Strokes can also cause other symptoms that are not typical of Bell’s palsy, including:

  • blurred vision
  • confusion
  • dizziness
  • headache
  • lack of coordination
  • trouble walking
  • problems with speech and speech comprehension

The symptoms of both conditions start suddenly and without warning. If you’re not sure which condition you or someone else is experiencing, seek emergency medical care right away.

Bell’s palsy is linked to problems with the seventh cranial nerve, which controls facial movements. But it’s not always clear why this nerve stops working properly.

Sometimes, damage to the seventh cranial nerve can be due to an existing viral or bacterial infection such as herpes, HIV, or Lyme disease. Other possible triggers include stress, lack of sleep, and minor illnesses.

The most common type of stroke, known as an ischemic stroke, occurs when a clot or plaque blocks blood flow to your brain.

A blockage affecting the seventh cranial nerve can cause facial sagging similar to Bell’s palsy. But a stroke also causes damage in other areas of your brain.

Bell’s palsy and stroke share several risk factors, as the table below shows.

Risk factorBell’s palsyStroke
high blood pressure
respiratory infections
physical inactivity
inadequate diet

Doctors use a process called differential diagnosis to confirm the cause of facial paralysis. Differential diagnosis involves asking questions and conducting tests not only to identify the cause of your symptoms but also to rule out other likely causes.

For example, even if your doctor suspects Bell’s palsy, they’ll gather enough information about your condition to rule out a stroke, and vice versa.

In addition to asking questions about your medical history and symptoms and performing a physical exam, your doctor may order some of the following tests:

The most common medications for Bell’s palsy are:

Treatment might also involve eye drops, physical therapy, acupuncture, massage, or surgery.

Stroke treatments depend on the type of stroke and its severity. Some common emergency treatments for ischemic strokes are:

  • aspirin or other medication to thin your blood and break up a blood clot
  • surgery to remove a blood clot
  • surgery to ease brain swelling

Bell’s palsy often goes away completely without treatment, but seeking treatment can improve your chances of making a full recovery.

On the other hand, the outlook after a stroke varies. Your likelihood of a full recovery depends on how quickly you receive medical care. Your age and your health status before the stroke can also affect your outlook.

Stroke generally increases your risk of serious health complications. The authors of a 2019 study analyzed stroke registry data from nearly 23,000 people in Sweden. They found that among people who had an ischemic stroke, nearly 80% had either died or required long-term care within 5 years.

This section discusses some common concerns about Bell’s palsy and stroke.

Does having Bell’s palsy increase your risk of stroke?

The authors of a 2021 study from Korea reported that people with Bell’s palsy had an increased risk of experiencing ischemic stroke.

What kind of stroke causes facial droop?

Ischemic strokes, hemorrhagic strokes, and transient ischemic attacks (which are sometimes called ministrokes) can all cause your face to droop.

What can Bell’s palsy be confused with?

Bell’s palsy can be confused with:

For how long will your face droop after a stroke?

It depends. Some people who experience a stroke return to regular facial strength within a few days or weeks, while others experience permanent facial weakness.

Both Bell’s palsy and stroke cause one-sided facial paralysis. But a stroke is more likely to cause other symptoms, such as weakness in one arm or leg, confusion, and slurred speech.

Unlike Bell’s palsy, stroke is a life threatening condition. Call 911 or local emergency services right away if you suspect that you or someone you know is having a stroke.