Do you know blood test ?

When you are asked by someone, what is blood test , you will know a little or more , because blood test is so common for us , when we go to hospital to exam ourselves. But not so many people can tell use what is blood test in correct meaning.

      Blood tests are a major part of many routine medical examinations. When you have a sickness , doctor will test your blood by hematology analyzer , or other clinical lab device with blood .

      During a blood test, a small amount of blood is taken from a vein, usually in the forearm, elbow, or hand using a thin needle and syringe or vacuum container system. The containers contain small amounts of chemicals that preserve the blood. A finger prick also may be used for some tests. The procedure is usually quick and easy, although it may cause some short-term discomfort and in some cases can require more than one attempt, particularly when many blood tests have recently been performed. The amount of blood taken is usually small, although it may seem like a lot to the patient.

      Lab workers process the blood and analyze it. They use either whole blood to count blood cells, or they separate the blood cells from the fluid that contains them. This fluid is called plasma or serum. The fluid is used to measure different substances in the blood. Since there are so many different blood tests available, many of which are expensive, the blood is only tested for a range of likely conditions or diseases that is specified by the ordering doctor. Blood tests alone cannot be used to diagnose or treat many diseases and medical problems—for example, only very specific types of cancer can be diagnosed by blood tests. It is often in combination with other factors—such as signs and symptoms, previous medical history, and results from other tests and procedures—that doctors use blood tests to help confirm a diagnosis.