The human body contains 50-60% water mainly in tissues and cells (e.g. a 70 kg adult carries 35-40 litres of water). Water is one of the components of blood. The blood volume of an adult amounts to 1/12 of the total body weight (e.g. 70 kg adult: 5-6 litres of blood). Major losses of blood volume (hypovolaemia) due to surgery, an accident with burns, or traumatic injuries, must be corrected immediately by giving infusions with blood volume substitutes.