There are a few simple rules testing. First of all, for the delivery of any analysis should be prepared - or in advance, in the evening or in the morning, just before the surrender. Most analyzes are encouraged to take on an empty stomach in the morning. The more complex the analysis, the stricter the rule: for example, if you eat before biochemical blood test, the results will differ from the true, may be a high level of glucose in the blood, from which it will be put misdiagnosed - diabetes. And after eating surrender tests for HIV infection may even lead to false-positive results.
For a regular urine test shall also often the first morning sample in which the maximum concentration not only of sex hormones (they stand out from 4 to 6 o'clock in the morning), but also protein, epithelial cells and other popular figures.
Instrumental analysis also largely dealt on an empty stomach - to the bolus moving through the digestive tract, does not interfere with inspection. Ultrasound and CT of the abdomen first need to take measures to avoid the occurrence of gases that create an air layer between the body and the sensor, preventing quality inspection. This is achieved by compliance with certain diet, administration of activated charcoal and other sorbents. Pawn qualitative examination of the large intestine - the perfect preparation, which is better to start in a few days. From the diet excludes all greasy, fried, irritable bowel and promotes increased formation of gas. Then, one day prior to the study, consistently placed several enemas for a thorough cleansing of all the twists and folds of the colon.
And just before the X-rays need not prepare any particular way. For more than a hundred years, it is one of the most simple, at least for today, and not the most informative method of research bones, lungs, small intestine.