A blood test is a blood sample given by a doctor to evaluate a patient’s health and detect or refine the detection of certain diseases and infections. Several types of analyses can be performed using the blood test. These analyses are carried out on various machines. This is why several tubes are frequently used.
What do blood tests reveal?
A doctor may decide to take a blood sample from a patient for a variety of reasons. The patient may be prescribed a blood test at a private clinic established in Montreal for:
- Screening: virus detection, cholesterol test
- Diagnosis due to illness: look for bacteria, active viral infections, inflammation, autoimmune disease antibodies, and so on.
- Examine the effects of a disease on the body: association with renal insufficiency, hepatic insufficiency
- Look for a genetic disease or the presence of a tumour marker.
Many diseases can be detected using blood tests
The analyses can provide important information, such as genes or tumour markers that reveal the presence of certain cancers, as well as detect many pathologies affecting various systems of the human body. However, while some pathologies, such as diabetes, bloodstream cancer (leukemia, lymphoma), and prostate cancer, can be diagnosed with a simple blood test, others require further investigation. The blood test is then used as a guideline.
When should the sample be taken?
Fasting is usually required in order to accurately assess blood sugar and lipid (cholesterol) levels. Ideally, you should ask your doctor or the laboratory. If the test must be performed on an empty stomach, schedule it in the morning and remember to pack a breakfast in your bag, something to fill your stomach after the blood test.
It’s important to know that no medication precludes the use of a blood test.
Interpreting blood test results: the blood count
A blood count measures the number and quality of blood cells, specifically white blood cells, red blood cells, and platelets. Using an optical method, the machine will provide a very precise measurement of the quantity of each type of blood cell. If the blood sample is abnormal, it will be spread on a glass slide and stained before being examined under a microscope by a biologist who will comment on the shape, size, or presence of abnormal cells. We look at the red blood cells and the average blood volume to interpret the results of this test.
Blood tests are useful for detecting diseases that are not visible to the naked eye.
It is recommended that blood tests be performed at least once a year in order to detect diseases as soon as possible.