Body fluid

[1] In lean healthy adult men, the total body water is about 60% (60–67%) of the total body weight; it is usually slightly lower in women (52–55%).

A lean 70 kg (150 lb) man, for example, has about 42 (42–47) liters of water in his body.

The total body of water is divided into fluid compartments,[1] between the intracellular fluid compartment (also called space, or volume) and the extracellular fluid (ECF) compartment (space, volume) in a two-to-one ratio: 28 (28–32) liters are inside cells and 14 (14–15) liters are outside cells.

[5] Clinical samples are generally defined as non-infectious human or animal materials including blood, saliva, excreta, body tissue and tissue fluids, and also FDA-approved pharmaceuticals that are blood products.

[7] In medical contexts, it is a specimen taken for diagnostic examination or evaluation, and for identification of disease or condition.

Intracellular and extracellular fluid compartments. The extracellular fluid compartment is further subdivided into the interstitial fluid and the intravascular fluid compartments.