Why is my blood so dark?

«Brave» patients who watch their samples being taken are frequently worried when they see the colour of their blood.

Don’t worry, it’s normal! Your blood is dark because it is venous blood which is returning to the heart and so contains little oxygen. The arterial blood leaving the lungs contains a large amount of oxygen and appears redder and less dark.

If your blood is dark this doesn’t mean that you are necessarily really ill!

And blood only appears really red on a screen – just like at the cinema!

Please do not hesitate to contact a laboratory biologist if you have any further questions.
Tél. : (+352) 488 288-1