J01.0: Acute maxillary sinusitis

One of your sinuses has become inflamed. The maxillary sinus is affected.

The sinuses are cavities in the skull that are filled with air. They make the head lighter and influence the sound of the voice. Air is moistened and warmed up in the sinuses. The sinuses have an inner lining of a moist and smooth membrane. This inner membrane is also called the mucous membrane. The mucous membrane produces fluid. The sinuses are connected to the nose via an opening. As a result, fluid can run out of the sinuses into the nose.

You have an inflammation in your maxillary sinus. The maxillary sinus is in the upper jawbone.

When there is an inflammation, the mucous membrane swells up. The swelling can block the connection to the nose. As a result, fluid accumulates in the sinus. This can cause headaches, fever and abnormal fatigue.

Additional indicator

On medical documents, the ICD code is often appended by letters that indicate the diagnostic certainty or the affected side of the body.

  • G: Confirmed diagnosis
  • V: Tentative diagnosis
  • Z: Condition after
  • A: Excluded diagnosis
  • L: Left
  • R: Right
  • B: Both sides

Further information


This information is not intended for self-diagnosis and does not replace professional medical advice from a doctor. If you find an ICD code on a personal medical document, please also note the additional indicator used for diagnostic confidence.
Your doctor will assist you with any health-related questions and explain the ICD diagnosis code to you in a direct consultation if necessary.


Provided by the non-profit organization “Was hab’ ich?” gemeinnützige GmbH on behalf of the Federal Ministry of Health (BMG).