Last Reviewed: 25th April 2017.
A blood test is the analysis of a blood sample from a patient to find naturally-occurring or foreign chemical or cellular components.
A blood test can be done to analyze your blood for signs of problems, such as abnormal electrolyte balance, abnormal kidney function, abnormal liver functions, anaemia (lack of oxygen carrying red blood cells), low platelets, high amount of white blood cells, your blood type, the presence of drugs, and levels of different medications.
Today, blood tests can do many things, because doctors and scientists have identified many substances in the blood that can tell you if you have an infection, an autoimmune disease, a marker for cancer, inherited diseases, and even blood clots or heart failure. Blood tests are also used to tell your doctor if you are having a heart attack.
Blood is withdrawn from a vein in the arm, or by means of a prick to the
If during the course of an examination your doctor uncovers an issue which may be indicative of a problem, your doctor may be able to find further information about your condition by taking a blood sample and testing it for certain substances. Symptoms that may prompt a blood test include:
Common things that your doctor or your healthcare practitioner would want to check for in your blood include:
The following are the common blood tests and what they mean:
This is a blood test to check your blood count. This is perhaps one of the most commonly-used blood tests in the world.
In the UK and many part of the English-speaking world, it is referred to as Full Blood Count or FBC. In North America, it is referred to as the Complete Blood count.
This test checks for:
Haemoglobin (Hb) is the substance in the blood that gives it the red colour. It is what carries oxygen in the blood to the body tissue and it is made from iron and protein. Normal hemoglobin level is about 12 to 16 in women and 14 to 18 in men. Low levels below 10 in anybody is referred to as anaemia, or shortage of red blood cells.
White Blood Count or WBC
White blood cells, if they are increased, can be an indicator of infection, or even types of leukemia. They are the cells your body normally produces in your bone marrow to protect you against infection. Normal levels of white blood cells in an adult Caucasian is 4000 to 11000 per dl and 2,500 to 8,500 in people of Afro-Caribbean descent.
Platelets are the cells that form clots and help your body heal bleeding wounds by sticking together and forming a plug. However, platelets can also clog your blood vessels if they are narrowed by atherosclerotic heart disease, for example. A big clot will obstruct the blood vessels.
For this blood
test, blood will be drawn from the vein in your arm and siphoned into a special
tube for laboratory testing. The blood is tested for hemoglobin levels in the
red blood cells, which can help your doctor if you have anaemia caused by iron
deficiency. Iron produces the molecule heme, which carries oxygen in the red
blood cells throughout your body to your tissues.
When your blood goes through the centrifuge, a spinner, the blood cells spin to the bottom to make a sediment, and the clear liquid on top is called plasma. The laboratory technicians will put the sediment under a microscope and will examine it and count how many red blood cells, white blood cells, and platelets are in the sediment per square millimeter.
Your body’s cells need certain molecules called electrolytes, to function. These are also referred to as blood salts. They include:
These are also referred to DAX or blood urea nitrogen and electrolytes. They are required for the maintenance of electrical balance in your body, transmission of nerve impulses, blood pressure control, water balance and more.
Depletion of your blood salts or electrolytes could lead to:
Any abnormality in the natural level and balance of these chemicals could lead to illness. Illnesses like diarrhoea and vomiting can also lead to excessive loss of these chemicals.
There are many reasons that your body has been unable to keep your electrolytes balanced, and one reason may be problems with your kidneys, which help control the excretion and balance of these elements. Kidney disease may keep you from having the right amounts of electrolytes for your cells to function.
Some drugs can also cause imbalances of electrolytes, which can be more
dangerous than we think. As an example, executions in the United States call
for a "lethal injection" that contains excess potassium because large
amounts of potassium can stop the heart.
Whether abdominal pain or another
condition, an imbalance of fluids and electrolytes, can lead to kidney
problems. Kidney problems are diagnosed using a kidney function test, which is
among the top blood tests administered to diagnose conditions.
Your liver is the site of many activities:
Testing for liver function is a frequently requested blood test for
abdominal pain amongst other conditions.
Fatty liver disease, excessive alcohol intake, metabolic syndrome, drugs like statins are all common causes of elevated liver function test, especially the GGT.
There are some chemicals in your blood that are released by damaged or injured cells. Such injury could be from infection, trauma, problems with the immune system, or even cancer. In many conditions that causes abdominal pain, important inflammatory markers or indicators of inflammation often tested in the blood include:
CRP (Cryo-Reactive Protein)
CRP is a protein produced by the liver in response to inflammation - be it from infection or any other causes of inflammation. A normal level of CRP is between zero (0) to Eight (8). Levels higher than 10 indicate an ongoing acute inflammation.
ESR (Erythrocyte Sedimentation Rate)
ESR is another marker of inflammation often checked in the blood. ESR
could be raised in chronic inflammation too as in acute inflammation.
Cancer cells sometimes release special chemicals into the bloodstream, like prostate-specific-antigen (PSA), which can be used to help your doctor make a cancer diagnosis. Tumour markers are substances found in abnormal quantity, usually when there is the presence of a type of tumor or cancer in the body.
Though a high amount of any of these chemicals is likely to indicate the presence of a tumour, they generally tend to have low level of accuracy in predicting the presence of cancers.
Tumor markers are best used to track recovery or recurrence in patients already diagnosed with a known cancer.
Common tumour markers requested in blood test include:
Every month, researchers
are finding more chemicals in the blood to analyze to help your doctor make a
diagnosis. Because a blood test is pretty simple to do, it is useful to be able
to understand the purpose of all the chemicals in the blood.
Common and important blood
tests that may be helpful in the diagnosis of abdominal pain and other related
Most people don’t know you
can order most blood tests online yourself, without a medical degree and
without a prescription. Go to the True Health Labs (affiliate
links) and see what tests they currently have available and order your test.
Yes, you can be in control of what you want tested.