Medical Questions » Pathology Questions » Question No. 774
| Question: | My doctor wants me to have a blood test, but I am scared stiff. What actually happens during a blood test? Does it hurt? |
| Answer: | The doctor may take the blood in the surgery or you may be asked to go to a nearby pathology clinic. Either way, the sample will be sent to a laboratory for analysis, unless a relatively simple test is required, in which case the doctor may have the necessary equipment in the surgery to perform the analysis (eg. for blood sugar).
Blood is extracted by inserting a hollow needle into a vein and allowing an amount of blood to flow into an attached tube. The blood will usually be taken from a vein at the bend in your elbow, but if that is not sufficiently prominent, the nurse may try your forearm or the back of your hand. It takes only a minute or so. Once the nurse has sufficient blood for the tests that have been ordered, the needle will be withdrawn and a dressing or cotton wool pressed on to the point of entry to stop the flow. You will need to leave it in place for half an hour or so until the blood clots naturally.
Sometimes the blood can be taken at any time of the day, but if the test is to measure your metabolism (how your body converts food into energy), the test must be performed in the early morning after a 12 hour fast, or at particular times after you have eaten a certain measured amount of food.
Blood tests to measure the amount of certain drugs in the system are also taken at specific times after the tablets are swallowed.
Blood tests hurt far less than a normal injection such as a flu shot because nothing is injected. If you do not watch the nurse, you will barely notice the discomfort, which will be no worse than having someone pinch your skin.
|
|
|
