Facial Paralysis: Causes, Symptoms, and Treatment

It can be a sign of different medical issues

Facial paralysis is difficulty moving part of the face, and it can be a serious symptom. Usually, facial paralysis affects one side of the face. It may affect the whole side or only the upper or lower part of the face. It rarely affects both sides.

Symptoms include slurred speech, drooling, dry eyes, and more. Facial weakness is a medical emergency because a stroke (a blockage of blood flow or bleeding in the brain) is one of the potential causes.

This article will discuss potential causes of facial paralysis, symptoms, diagnostic procedures, and treatment.

Man recovering from stroke, with facial paralysis

Renata Angerami / Getty Images

Facial Paralysis Causes

There are many causes of facial paralysis. It can be result from brain damage or nerve damage. Some conditions causing facial weakness are temporary and easily treatable, while others are serious and even life-threatening. You should never ignore facial weakness, and you should get urgent medical attention if you develop any symptoms. 

Bell’s Palsy 

Bell’s palsy causes paralysis of one side of the face, usually without other symptoms. It is believed to result from inflammation, but it often doesn’t have a known cause. Bell’s palsy is not dangerous, but more serious causes need to be ruled out before this diagnosis is made.

The condition usually begins to improve on its own within a few weeks, but full improvement can take a year or longer. Treatment with oral steroids may speed up the resolution of Bell’s palsy.

An eye patch may be recommended to prevent corneal damage (damage to the surface of the eye) if the eyelid can’t close.


A stroke is brain damage due to insufficient blood supply to a region of the brain. A stroke can cause weakness on one side of the face or body.

When a stroke causes facial weakness, it may cause other associated symptoms, such as double vision, dizziness and balance problems, or weakness of one side of the body. Depending on the region of brain damage, the facial weakness can either be on the same or opposite side as the weakness of the body.

Facial weakness from a stroke usually is permanent, but there can be some improvement over time and with physical therapy.


The facial nerve, also known as cranial nerve 7, controls facial movement. It can be injured due to trauma. Sometimes an injury of the soft tissue of the face may cause swelling around the nerve, which can result in temporary facial weakness until the swelling goes away.

The weakness of the face from facial nerve trauma will correspond to the specific branches of the facial nerve that are injured. An injury that cuts the nerve is expected to cause permanent facial weakness. 


Several other conditions can cause facial weakness or may cause the face to appear weak, including: 

  • Multiple sclerosis (MS): This condition usually begins in adulthood and affects the brain and spinal cord, with neurological symptoms that may partially resolve and then recur. MS can cause facial weakness or numbness on one side of the face, vision changes, balance problems, and weakness or numbness on one side of the body. 
  • Myasthenia gravis: This condition affects the communication between certain nerves and muscles. It can cause droopy eyelids and weakness of the upper body, usually along with fatigue. 
  • Cerebral palsy: This condition is present at birth due to brain damage during fetal development, or right after birth. It causes permanent neurological problems, and it can cause facial weakness on one or both sides of the face. 
  • Neuropathy: Neuropathy is disease of any nerve in the body. Facial neuropathy is not common. It can result from inflammation or disease. 
  • Infection: Some infections, including viral infections or severe dental infections, can cause damage or inflammation of the facial nerve, leading to facial paralysis. 
  • Cancer: A tumor in the face or spreading from elsewhere in the body may cause swelling and facial weakness or may compress the facial nerve. 
  • Anaphylaxis: This life-threatening allergic reaction can cause swelling of the face and lips, impairing movement of the face.
  • Amyotrophic lateral sclerosis (ALS): This degenerative disease affects muscle movement throughout the body, including the face. 

Facial Paralysis Symptoms

Paralysis can include partial weakness (paresis) or complete weakness (plegia). Paralysis of one side of the face is described as hemifacial paralysis

Symptoms of facial paralysis can include any of the following:

  • Inability to open the eyelid, sometimes with blurred vision 
  • Inability to close the eyelid, often with dry eyes
  • Flat appearance of some of the normal creases of the face
  • Droopy appearance of the cheeks or mouth 
  • Drooling 
  • Slurred speech 
  • Difficulty chewing 

Sometimes tingling sensations, numbness, pain, or a loss of sensation can accompany facial paralysis if the sensory nerve of the face (trigeminal nerve) or areas of the brain controlling facial sensation are affected.  

When to See a Healthcare Provider

It's important to get prompt medical attention if you develop new weakness in any part of your face, including your eyelid, cheek, or mouth.


Facial paralysis is considered a medical emergency. If you experience weakness in your face, a healthcare provider will take a medical history, asking details about your symptoms, the timing, and your past medical history.  You will have a physical examination, which includes checking your temperature and vital signs. 

During your neurological examination, your healthcare provider will check whether your forehead is weak on one or both sides. This is a crucial aspect of the evaluation of facial weakness.

When facial weakness is caused by a stroke, only one side of the forehead is weak. When facial weakness is caused by nerve damage, both sides of the forehead are weak. 

Other tests you might need include:

  • Brain imaging: This includes a computed tomography (CT) scan or magnetic resonance imaging (MRI), which can help identify a stroke, MS, or a tumor.
  • Blood tests: Infections and inflammation can cause changes in blood test results. 
  • Lumbar puncture: This is an invasive test that’s done to collect cerebrospinal fluid. The results may point to an infection, MS, or inflammatory disease.
  • Tension test: This test involves repeated testing of muscle movements after taking medication. It can be used in the evaluation of myasthenia gravis. 
  • Electromyography (EMG) or nerve conduction study (NCV): These electrical muscle and nerve tests can detect patterns consistent with neuropathy, ALS, and nerve injuries.

Facial Paralysis Treatment

Facial paralysis treatment depends on the cause. For example, an MS exacerbation is treated with steroids, and a bacterial mouth or tooth infection may be treated with antibiotics and dental care.

If facial movement is still impaired after treatment, rehabilitation with physical therapy and speech and swallow therapy can be helpful.

Sometimes, nerve damage can be treated surgically. Different techniques may be used to repair the nerve or muscle and to prevent further damage. Studies suggest that surgery for the treatment of facial paralysis is safe and often results in good outcomes in terms of restored facial movements.


Surgical treatment for facial paralysis can involve procedures such as drainage of an abscess (a walled-off area of infection and pus), removal of a tumor, or repair of the nerve. Sometimes these approaches can prevent lasting nerve damage and restore facial movement.

Nerve Transfers

A nerve transfer may be possible in some circumstances, such as after a nerve injury. This is a very complicated procedure that requires extensive planning prior to surgery.

Cross-Facial Nerve Graft

A facial nerve graft often is a multistep process, with the goal of restoring facial movement. Nerve grafts may also involve a muscle transfer.

Masseter Muscle Transfer

Muscle transfer for facial paralysis treatment is aimed at restoring symmetry of the face. This procedure involves the removal of muscle from another area of the body and grafting it into the weak area.

It may be considered when the muscle in the affected area has atrophied (shrunk) and cannot move properly. The newly placed muscle will be positioned so it can receive proper blood supply and nerve stimulation.

Hypoglossal Nerve

The hypoglossal nerve is one of the nerves that can be transferred to restore facial movement after facial paralysis.


Facial paralysis has many different causes, with Bell’s palsy, stroke, and injury being the most common. The outcome and treatment depend on the cause. Serious complications can include eye damage and swallowing difficulties.

Sometimes long-term facial weakness may improve with surgical repair, which can involve procedures such as nerve repair or nerve or muscle transfer. Rehabilitation may be necessary to improve movement and control of the facial muscles.

A Word From Verywell

Facial paralysis can be frightening and disabling. It’s important to get medical attention for facial paralysis right away. A speedy diagnosis and prompt treatment can improve the outcome. You might need rehabilitation, such as speech and swallowing therapy, so that you can chew and eat safely and communicate effectively.

Frequently Asked Questions: 

Frequently Asked Questions

  • Can facial paralysis be cured?

    Sometimes facial paralysis, including Bell’s palsy, can be cured with treatment. Other times, as with a stroke, it is permanent or may only partially improve. Surgical treatment may help restore movement and symmetry of the face in some cases.

  • What are the early signs of facial paralysis?

    Early signs of facial paralysis may include loss of the crease in the lower part of the cheek, drooling, or dry eyes. Sometimes, facial weakness is obvious, and one side of the face may appear droopy.

  • Can stress cause facial paralysis?

    Stress does not cause facial weakness, but sometimes stress may contribute to Bell’s palsy. Facial paralysis of all types can increase anxiety.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Heidi Moawad, MD
Heidi Moawad is a neurologist and expert in the field of brain health and neurological disorders. Dr. Moawad regularly writes and edits health and career content for medical books and publications.