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Medically reviewed by Last updated on Apr 2, 2024.

What is mastoiditis?

Mastoiditis is an infection in the mastoid bone of your skull. The mastoid bone is located behind your ear. Mastoiditis is often caused by an ear infection that spreads. Your risk for mastoiditis may increase if you have a chronic condition that weakens your immune system. Your ear canal swells and traps fluid inside your ear. Trapped fluid causes bacteria to grow and spread to your mastoid bone.

Ear Anatomy

What are the signs and symptoms of mastoiditis?

How is mastoiditis diagnosed?

Your healthcare provider will examine your ear, and ask about your signs and symptoms. Your provider may feel the outside of your ear for pain or swelling. Your provider may check your hearing. You may also need any of the following:

How is mastoiditis treated?

You may need to spend a few days in the hospital for treatment and monitoring. You may be cared for by a healthcare provider with training in ear, nose, and throat conditions. You may also need any of the following:

What can I do to care for my ears?

Keep your ears dry. Do not allow water or liquids to get into your ears. Use earplugs as directed when you shower or swim.

Have someone call your local emergency number (911 in the US) if:

When should I seek immediate care?

When should I call my doctor?

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. 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.

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