Plasma density.

The plasma density is defined by total amount of plasma cations and anions. 1048 - 1055 g/cm³ is a norm. Changes in the plasma density are attributed to the disorders of water metabolism. These processes are greatly effected by antidiuretic hormone. It can be seen with Conn’s syndrome, which is associated with the changes in aldosterone level. When plasma density is lower 1056 g/cm³, this results in blood pressure instability, hypodynamia, sometimes convulsions.

Blood is a liquid tissue composed of roughly 55% fluid plasma and 45% cells. The three main types of cells in blood are red blood cells, white blood cells and platelets. 92% of blood plasma is composed of water and the other 8% is composed of proteins, metabolites and ions. The density of blood plasma is approximately 1025 kg/m3 and the density of blood cells circulating in the blood is approximately 1125 kg/m3. Blood plasma and its contents is known as whole blood. The average density of whole blood for a human is about 1060 g/cm³.

Blood density changes with body posture. Venous blood density is higher when a person is standing than when he is sitting. The following charts show the venous blood densities of 6 subjects as they change body positions during 10 minutes.