A complete blood count (CBC) or the routine blood test is a test that evaluates the overall health of an individual and detects a wide range of ailments like anemia, infection, and leukemia.
A routine blood test measures several components and features of an individual’s blood that includes:
Red blood cells: oxygen carriers.
White blood cells: infection fighters.
Hemoglobin: Oxygen carrying proteins present in the red blood cells.
Hematocrit: the proportion of red blood cells to the plasma, in the blood.
Platelets: blood clotting aiders.
Abnormal increases or decreases in cell counts as revealed in a complete blood count may indicate an underlying medical condition that calls for further medical attention.
Other common blood evaluations that are commonly sought by many physicians include:
- A basic metabolic panel that checks a person heart, kidney, and liver function by looking at the blood glucose, calcium, and electrolyte levels.
- A lipoprotein assay that measures levels of fats in the blood, like good cholesterol (HDL), bad cholesterol (LDL), and triglycerides are also sought to check for heart ailment risks.
What are the things that most doctors fail to reveal about blood tests?
The below list includes pointers that some doctors may not reveal about the blood tests.
The normal reference range for a blood evaluation differs among sexes.
The normal ranges for any blood assay are not the same for both the sexes. For instance, the normal range for hemoglobin for hemoglobin in men and women are 13.5 to 17.5 grams and 12.0 to 15.5 grams per deciliter, respectively.
Normal range may or may not change as a person ages.
Not all blood tests are subject to change with age. But certain blood tests do depend on an individual’s age. For example, a hemoglobin level of about 11 to 13 grams/deciliter (g/dl) is normal in children, while the ranges differ in adults. But for other tests, such as LDL cholesterol, a level less than 100 milligrams/deciliter is optimal regardless of age.
A ‘positive’ assay result may not be a positive news.
Some blood assays like sickle cell anemia, HIV, hepatitis C, and the BRCA1 or BRCA2 gene assay search for molecular markers or disease-causing agents in the blood sample which indicate the ailments presence.
A ‘negative’ assay result may reveal positive information.
A negative outcome in some blood assays is not a bad result as it literally means. A negative outcome means that the evaluation failed to detect a disease marker or a risk factor that it was seeking with respect to a health condition. For instance, when an individual is prescribed a blood test to check for an infectious disease like interferon-gamma release assay for tuberculosis; getting back a negative result is a good news as it means that no evidence of an infection was detected
The possibility of a false positive test outcome.
There are many disorders wherein the tests depend on factors that are also influenced by other body conditions. For example, a test for HIV can come falsely positive even when the person is infected. These cases occur due to the HIV test measures antibodies in the blood. More precisely if an individual suffers from other immune conditions such as rheumatoid arthritis, his /her assay results can be false.
The occurrence of a false negative test result.
Predominantly a test fails to pick up evidence of an ailment or condition, even though a person actually does have it. for instance, if an individual is tested for Lyme disease within the first few weeks of an infection, he or she may get a negative outcome because the body may not have developed antibodies for the particular infection.
The outcomes of an assay do not always indicate an ailment or disorder.
The assay results which fail to fall in the normal reference range may not always indicate a disease. The factors that can alleviate test outcomes are:
- Being on some medication.
- Drinking alcohol the night before the test.
- Eating foods that needed to be refrained from before the evaluation. It is always recommended to ask the doctor about the dos and don’ts of a test before getting it done.
The values may differ between labs.
Technicians of a diagnostic center compare the blood test outcomes with a range that is considered normal for that laboratory or center. The lab’s reference range is solely based on the test outcomes of many people previously tested in that lab.
A recent report from the Food and Drug Administration, states that the reference levels for various assays may or may not be the same between various lab’s. Hence change it should not be surprising to find variability while comparing two blood report outcomes of an individual obtained from two different diagnostic centers.
Note: For an accurate result the physicians always recommended to get the test assays done at the same center each time.
Mistakes tend to occur.
Although the mix-ups of blood test samples are rare, they do happen. The handling of a blood sample before analyzation is also seen to affect the results. For Instance, if the sample is collected in the wrong container, shaken inappropriately, stored for long period or at the wrong temperature, an erroneous result can be obtained.
The good news is often ‘skipped’
In cases when the assay outcomes fall within normal ranges, the doctor might not approach you for reports or may also send the report with very little explanation. However, it always recommended discussing the blood test results whether they are normal or not. Even if things appear normal for an individual, following up with the doctor about the blood test results is a wise decision.
Having a basic knowledge about the blood evaluations not only helps a person to take the right decisions about one’s diet and lifestyle but also relieves the stress that occurs in the time span between the test report arrival and the doctor’s consultation.