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Horner Syndrome


Horner syndrome

is a nerve condition that affects one side of your face. The condition is caused by an injury to a nerve that controls that side of the face. Horner syndrome may be a sign of a serious condition such as a stroke or aneurysm. It is important to seek immediate care if you develop other problems, such as head or neck pain.

Common signs and symptoms of Horner syndrome:

  • Smaller pupil in one eye, and the pupil does not dilate (widen) well
  • Drooping upper eyelid, or a higher lower eyelid
  • Less sweating on one or both sides of your face or in a small area on one side
  • Redness on the white part of your eye

Seek care immediately if:

  • You have head or neck pain.
  • You have sudden vision changes or problems.
  • You are dizzy or weak.

Contact your healthcare provider if:

  • You have new or worsening signs or symptoms.
  • You have questions or concerns about your condition or care.


Treatment of Horner syndrome depends on the cause. Signs and symptoms usually go away after the cause is treated. You may need any of the following:

  • An ophthalmologist (eye specialist) may be able to find and treat vision problems that develop.
  • Occupational therapy may be helpful if you have trouble seeing because of eyelid drooping. An occupational therapist can help you strengthen affected eye muscles. The therapist can also help you find ways to do your work or daily activities more easily if you are having vision problems.
  • Surgery or medication may be used if you have severe eyelid drooping.

Follow up with your healthcare provider as directed:

Your healthcare provider may refer you to a nerve or eye specialist. Write down your questions so you remember to ask them during your visits.

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The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

Learn more about Horner Syndrome (Ambulatory Care)

Associated drugs

IBM Watson Micromedex

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.