R55: Syncope and collapse

You were unconscious for a short time.

Insufficient blood reaching the brain for a short time causes you to become unconscious. There are a number of reasons why you can lose consciousness. Many of them are not dangerous.

Normally, the body adjusts the heartbeat and the width of the blood vessels to the situation. Sometimes the body cannot adjust to the situation properly. This causes you to lose consciousness. This can happen if you stand for a long time or experience emotional distress.

You can also pass out if the heart can no longer pump enough blood into the body. This can happen when the heart is beating much too slowly or too quickly. You may also pass out if the heart is beating irregularly. A heart valve that has stopped working can be another reason.

You can also pass out if the brain doesn’t get enough blood when you change position. Changing position is when you stand up too quickly, for example.

You can also pass out if you don’t have enough fluid in the body.

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).