What is high red blood cell count?

Red blood cells are one of the major components of blood, along with white blood cells and platelets. Red blood cells help carry oxygen throughout the body.

Doctors measure your red blood cell count to help diagnose medical conditions and learn more about your health. A high red blood cell count means the number of red blood cells in your bloodstream is higher than normal. Normal red blood cell counts are:

  • For men, 4.7 to 6.1 million red blood cells per microliter of blood
  • For women, 4.2 to 5.4 million red blood cells per microliter of blood
  • For children, 4.0 to 5.5 million red blood cells per microliter of blood

Doctors typically find a high red blood cell count during tests for another health issue. You may need more tests to determine what’s causing the higher levels. These may include tests to look for conditions that cause your body to produce too many red blood cells, such as heart failure, or disorders that restrict your oxygen supply, such as sleep apnea.

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