All in vein

Blood is the life-maintaining fluid that circulates through the body's heart, arteries, veins and capillaries. The blood carries away waste matter and carbon dioxide and brings nourishment to every cell in the body. A blood test is probably one of the most common investigations undertaken by a GP and can lead to a wealth of information to enable the GP and underwriter to make their assessment. The adult human body contains approximately five litres of blood and makes up 7% to 8% of body weight. Blood is made up of about 78% water and 22% cells. The liquid portion of the blood is terme...