If you took a sample of blood and put in a plain glass tube and waited, you would then see that the red part of the blood would form a clot, and above it you would see some straw coloured fluid.

In the UK and Europe a Doctor orders only the blood tests he/she requires. The Doctor makes a list on the blood test form of the ones he wants the Laboratory to do.

Coronary angiography is an investigation that looks at how well the arteries surrounding are working and if they are fully open.

If your Doctor suspests you may have a kidney stone or some problem in your kidney or bladder, you will be sent for a special kind of X-Ray called an Intra-Venous Urogram, IVU for short.

The commonest microbiology test done is the urine sample that is sent to the laboratory to see if there is an infection in the urine.

MRI (magnetic resonance imaging) is a fairly new technique that has been used since the 1980s.

We now taken for granted that USS is available. They were first introduced on an experimental basis in the early 1970s. Their first use was in pregnancy. The basis for their use is very similar to the old fashioned way submarines were detected in the Second World War.