Usually, the brain moves muscles by sending them signals through the nerves. It is an automatic process that people do not even notice happening. Sometimes, an interruption to this process leads to paralysis. When the problem affects the facial nerves, it can result in facial paralysis.

In this article, we look at five causes of facial paralysis, along with the accompanying symptoms and treatment options.

We also explain when to see a doctor and how they will diagnose facial paralysis.

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A number of conditions can cause facial paralysis.

If a person suspects that someone is experiencing a stroke, they should perform the FAST check:

  • F for face: Ask the person to smile and check whether one side of the face is drooping.
  • A for arms: Ask the person to raise both arms and look for one arm drifting downward.
  • S for speech: Ask the person to repeat a simple phrase and listen to see whether their speech is unusual.
  • T for time: Call 911 immediately if any of these signs are present.

The Centers for Disease Control and Prevention (CDC) state that a stroke occurs when the brain does not get enough blood or when there is bleeding in the brain.

Blockages or ruptures in the blood vessels that supply the brain cause stroke. Stroke can affect the way the brain sends messages to the muscles of the body.

There are three different types of stroke:

  • Ischemic: This type of stroke represents 87% of all strokes and occurs when something, typically a blood clot, blocks the blood flow through the artery that supplies blood to the brain.
  • Hemorrhagic: This type of stroke occurs when an artery in the brain ruptures or leaks blood. This blood puts pressure on brain cells, which can damage them.
  • Transient ischemic attack: Also called a mini-stroke, this occurs when the blood flow becomes blocked for just a short period.

A stroke will come on suddenly and requires emergency medical attention.

Symptoms include:

  • numbness or weakness in one side of the body, affecting the face, arm, or leg
  • confusion
  • difficulty talking or understanding
  • vision problems in one or both eyes
  • difficulty walking
  • feeling dizzy
  • loss of balance and coordination
  • a severe headache


Anyone who has a stroke will require treatment in the hospital. Depending on the cause of the stroke, doctors will usually recommend drugs or an operation to stop the bleeding and save brain tissue.

Some people recover fully from a stroke, but others may have problems for a long time afterward. It can take anywhere from a few weeks to a few years to overcome the symptoms, and some people will have lifelong disabilities.

Bell’s palsy is a neurological disorder. It affects the seventh cranial nerve, which is one of the facial nerves, and leaves the person unable to move one side of their face.

According to the National Organization for Rare Disorders (NORD), it tends to come on suddenly and worsen over several hours.

People may be unable to move the muscles on one side of the face, and it might look smooth and expressionless. Sometimes, a person might not be able to close the eye on the affected side.

Before the paralysis, the person may experience:

  • a high temperature
  • pain behind the ear
  • stiffness in the neck
  • weakness or stiffness on one side of the face

Doctors do not know what causes Bell’s palsy. However, viruses and disorders of the immune system may be possible causes.

Learn more about the potential causes of Bell’s palsy here.


According to the NORD, in 80% of cases, Bell’s palsy will go away within 3 months. Most people get better without treatment.

However, a healthcare professional may suggest mild electrical stimulation and massage of the paralyzed muscles. This treatment can improve muscle tone and help prevent the loss of muscle function.

Oral corticosteroids can be effective in reducing the symptoms of Bell’s palsy. Some people may take antiviral medications alongside the corticosteroids.

If a person is unable to close their eye, they can use eye drops, goggles, or eyeglasses to protect it.

Black-legged ticks can carry bacteria. When the insects bite humans, these bacteria enter the person, and this can lead to Lyme disease.

The CDC state that the symptoms of Lyme disease can vary depending on the stage of the infection.

They note that the early signs and symptoms, which typically appear 3–30 days after the tick bite, can include:

  • fever
  • chills
  • headaches
  • fatigue
  • joint and muscle aches
  • swollen lymph nodes
  • erythema migrans rash

Later signs and symptoms, which can occur days or months after a tick bite, include:

  • a severe headache
  • neck stiffness
  • facial palsy
  • arthritis
  • intermittent pain in the muscles, tendons, joints, and bones
  • heart palpitations
  • dizziness
  • shortness of breath
  • nerve pain

Learn about Lyme disease symptoms in more detail here.


Doctors usually prescribe antibiotics to treat the condition.

If the diagnosis takes place when the disease is in the early stages, a person may only need a short course of oral antibiotics. However, more severe cases might require a longer course lasting 3–4 weeks.

Neurosarcoidosis is a type of sarcoidosis, which is a chronic inflammatory condition that occurs when the immune system has an excessive response.

While sarcoidosis primarily affects the lungs, neurosarcoidosis causes inflammation in the brain, spinal cord, or nerves.

According to the National Institute of Neurological Disorders and Stroke, the symptoms may start suddenly or come on slowly.

The symptoms include:

  • weakness in the muscles on one side of the face
  • headaches
  • seizures
  • memory loss
  • hallucinations
  • irritability and agitation
  • mood and behavior changes


Doctors tend to treat neurosarcoidosis with steroids. If that does not work, they might try drugs that modify or dampen the immune system.

About two-thirds of people with neurosarcoidosis will recover completely with treatment.

Others may experience symptom flare-ups from time to time.

A brain tumor may cause facial paralysis.

The symptoms might include:

  • headaches
  • seizures
  • difficulty articulating
  • difficulty speaking
  • loss of balance
  • personality changes
  • weakness or paralysis in one part or side of the body
  • vision changes
  • facial numbness
  • confusion


The treatment and outlook will depend on the type of brain tumor.

Doctors may recommend a mixture of surgery, chemotherapy, and radiation therapy to either remove the cancer cells or stop the tumor from growing.

To diagnose the cause of facial paralysis, a doctor will examine the person and ask questions about their medical history, lifestyle, and symptoms.

Other tests that they might perform include:

  • blood tests
  • imaging tests, such as an MRI
  • biopsies

Anyone who experiences facial paralysis should seek medical attention in case it is a sign of a serious health condition.

A person having a stroke needs emergency medical attention. The sooner they receive treatment, the more likely they are to recover. Anyone who suspects that someone is having a stroke should call 911 straightaway.

Facial paralysis happens when something interrupts the nerve signals between the brain and the muscles in the face.

Facial paralysis is a symptom of several health conditions, including Bell’s palsy, stroke, Lyme disease, neurosarcoidosis, and a brain tumor.

Anyone experiencing facial paralysis should speak to a doctor as soon as possible. People showing signs of a stroke need emergency medical attention.