Red blood count

A red blood cell count can be used to measure a decrease in the number of red blood cells (anaemia) or an increase(polycythaemia).



An increase in red blood cells is known as polycythaemia and a decrease is known as [anaemia](/health-library/conditions/anaemia-iron-deficiency).

A red blood cell (RBC) count is usually carried out as part of a full blood cell (FBC) count, and can help diagnose health conditions that affect the blood.

For example, if you have a high red blood cell count it could be due to a condition such as [congenital heart disease](/health-library/conditions/congenital-heart-disease) or [dehydration](/health-library/conditions/dehydration).

A low red blood cell count may be a sign that you have anaemia, internal bleeding, [kidney disease](/health-library/conditions/kidney-disease-chronic) or [malnutrition](/health-library/conditions/malnutrition) (when a person’s diet does not contain enough nutrients to meet their body's demands).

A low count may also be a sign of an iron deficiency or a vitamin B6, [B12 or folate deficiency](/health-library/conditions/vitamin-b12-and-folate-deficiency/#introduction).


::: body-ad-desktop
zones:: 232632,232357,232640
types:: 163
disclaimer:: AD
typeFilter:: native_ad
adCount:: 1

:::


error

 There was an error when submitting your feedback – have a screen break then try again in a few minutes.

Oh no, something’s gone wrong

ANY COMMENTS OR SUGGESTIONS?

initial

This isn’t helpful

This isn’t relevant

Something is wrong

This isn’t accurate

Please select one.

loading

success

We're listening – we use your feedback to improve your experience, and make our content more helpful.

Thank you for your feedback

References

Healthily's medical team

Article information

All of Healthily's articles undergo medical safety checks to verify that the information is medically safe. View more details in our <a href="/safety" target="_blank" rel="noopener noreferrer">safety page</a>, or read our <a href="/legal/editorial-policy-principles" target="_blank" rel="noopener noreferrer">editorial policy</a>.

A red blood cell count can be used to measure an increase or decrease in the number of red blood cells.