E87.1: Hypo-osmolality and hyponatraemia

Your blood sodium levels were too low.

Sodium helps regulate the moisture content in the body. Conversely, the water content in the body affects the sodium content in the blood. The sodium content is controlled by many processes. The sodium content in the blood must be in a specific range for the body to be able to function.

Your blood sodium levels were too low. If there is a lot of water in the blood for instance, the sodium content in the blood decreases. For example, that may occur if the kidneys no longer work properly and cannot excrete enough water. But you may also have too little sodium in your blood if you lose a lot of sodium. That can occur for instance due to vomiting or diarrhea.

If you have too little sodium in your blood, nausea and headaches may occur, for example. You may also be very sleepy. You may also lose consciousness or have seizures.

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.


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