What Are Blood Tests?
The fear of needles is real.
Just the mere thought of the thin, metallic object pricking into the skin can make our hairs stand on end.
Yet, it is one of the most useful and fundamental tools to assess one’s health.
Let us dive a little deeper into blood testing.
What types of Blood Tests are there?
Your doctor can order a lot of tests from just 1 vial of blood. The more basic ones include:
- Full Blood Count
This test looks at the overall components of your blood.
Red blood cells
These cells transport oxygen to our body cells. Lower levels indicate anemia.
White blood cells
These cells aid in fighting infections in our body. Raised or lowered cells are signs of infection or blood diseases.
Platelets
These cells prevent us from bleeding out by clotting our blood. Too many platelets can be due to infections like dengue, cancer or even inflammatory disorders like rheumatoid arthritis or inflammatory bowel disease.
Too few platelets can indicate of an infection too. Autoimmune diseases (immune thrombocytopenia caused by lupus or rheumatoid arthritis) or rare blood disorders like thrombotic thrombocytopenic purpura (where blood clots form in blood vessels all over the body, blocking blood flow to the whole body) can also lower our platelet levels.
Haemoglobin
They are found in red blood cells and play an important role in the transport of oxygen throughout our body. Similar to red blood cells, lower levels indicate anemia.
- Renal Function Tests
Have you ever wondered how our bodies filter out toxins and waste products?
Our kidneys come into play. They are essential in filtering out waste and toxins from our bodies, as well as regulating our blood pressure. They also play a fundamental role in keeping our body hydrated.
Doctors carry out renal function tests to look for any electrolyte imbalances.
Your doctor might order this test to assess your kidney function and their overall health. We can assess our electrolytes, urea, creatinine and glomerular filtration rate.
Electrolytes
Electrolytes in a renal function workup include sodium, potassium, chloride and calcium. Any abnormalities may also affect the function of other organs of your body, such as your heart and brain.
Urea and Creatinine
These two components are elevated in both acute and chronic kidney diseases.
Causes of chronic kidney disease include:
- Type 1 and Type 2 Diabetes Mellitus
- High blood pressure
- Inherited diseases like polycystic kidney disease
- Infection – pyelonephritis (infection of the kidneys)
Causes of acute kidney failure include:
- Massive fluid or blood loss
- Blood pressure medications
- Heart attack
- Severe burns
- Infection
Uric acid
The kidneys produce uric acid as a waste product. It is then transported from the blood to the kidneys to be passed out from the body as urine. A high uric acid level in the blood may indicate gout or kidney stones.
- Liver Function Tests
The liver is an important organ of our body. Although tiny in size (approximately 1.4kgs), it plays a crucial role in detoxification, metabolism and digestion.
Did you know? Our liver also stores vitamins (vitamins A, D, E and K) and produces bile! Bile is greenish-yellow in colour, and breaks down fat into fatty acids.
The test will measure the levels of:
- Total protein
- Albumin
- Globulin
- ALP
- ALT
- AST
- SST
- GGT
The results of the liver function tests are interpreted as a whole to assess for any liver cell damage.
ALT and AST are enzymes that aid in gluconeogenesis- the process of generating blood glucose. Elevated levels may be due to liver injury.
Causes of liver injury include:
- Chronic alcoholism
- Infections like hepatitis
- Congenital diseases like Gilbert syndrome
Elevated ALPs may signify damage to your bile duct system.
Other causes of abnormal test results include:
- Congestive heart failure
- Pancreatitis (inflammation of the pancreas)
- Liver cirrhosis
- Diabetes
- Severe side effects of certain medications
- Lipid studies
These groups of tests include:
- Total cholesterol
- HDL (‘good’ cholesterol)
- LDL (‘bad’ cholesterol)
- Triglycerides
- Cholesterol ratio
You might be at risk of developing high cholesterol if you have a family history of stroke or heart disease.
Other risk factors include diabetes mellitus, high blood pressure, overweight/ obesity, smoking, a poor diet or a sedentary lifestyle.
- Diabetic screening
1 in 5 Malaysians has diabetes. Nearly 49% are undiagnosed. That is, according to a National Health Survey done in 2019. With diabetic screenings, your doctor will be able to determine if you have (or are at risk of developing) diabetes mellitus.
Fasting plasma glucose
Diabetes: >7.0mmol/L
Prediabetes : 5.6-6.9 mmol/L
HbA1c
This stands for glycated haemoglobin. Glucose binds to your red blood cells for their entire lifespan -roughly 3 months. Hence, HbA1c levels are a good parameter for assessing your average blood glucose levels for the past 2-3 months.
Diabetes: >6.5%
Prediabetes: 5.7-6.4%
Your doctor might also use a glucometer or perform an oral glucose tolerance test (OGTT) to test your blood sugar levels.
Urine Sample
A routine blood screening will often include your urine sample too. Urine samples are also obtained while fasting, so as not to interfere with the results.
A urine FEME (full examination microscopy examination) will measure your urine chemistry, ketones, glucose, pH and specific gravity.
If you are a female, do let your doctor know if you are on your menses – as it can affect the results!
What Other Studies Can I Screen for?
The list is endless! The following below are not included in the mandatory blood screening, but your doctor might order specific tests if he/she suspects an underlying issue.
The following tests include:
- Thyroid profile
Your Thyroid Stimulating Hormone (TSH) levels are assessed. They are secreted by your pituitary gland, which tells your thyroid gland how much thyroid hormone to produce.
- H. Pylori antibody screening :
H. Pylori can be transmitted through fluid secretions (stools, vomit, saliva) or through contaminated food and drink.
- C- Reactive Protein (CRP)
CRP levels are a good indicator to screen for any heart disease. High levels indicate an increased risk of developing cardiovascular diseases like heart attack or stroke.
- Rheumatoid arthritis factor
This is a specific test to assess for rheumatoid arthritis- an autoimmune and inflammatory disease.
- Infectious disease screenings
Your doctor is able to screen for infections like syphilis, hepatitis B and HIV infections.
- ABO Group
The general population has 4 blood types – Blood Groups A, B, O and AB.
- Cancer screening
Your doctor might order relevant tests for you if you are present with symptoms of malignancy- unintentional weight loss, loss of appetite, fatigue or more specific symptoms.
Testing includes:
- AFP: Liver, ovarian and testicular cancer
- CEA: Bladder, breast, lung, ovarian and colon cancer
- CA 19.9: Pancreas cancer
- CA 125: Ovarian, endometrial and peritoneal cancer
- CA 153: Breast ca, liver, colon and pancreatic cancer
Why Should I Go for Regular Screenings?
Prevention is Better than Cure
Chronic diseases like diabetes, high blood pressure and high cholesterol are silent diseases until their late stages. Early detection can enable you to make necessary lifestyle changes and prevent the disease from progressing.
Early Detection of Cancer
Your doctor will be able to aggressively treat it during the early stages.
How Often Should I do Blood Screenings?
According to the American Academy of Family Physicians, it will depend on your age:
A general rule of thumb is:
18-39 years old: At least every 5 years
40-49 years old: At least every 2-3 years
≥50 years old: Annually
However, it may vary according to every individual’s overall health and well-being. Do talk to your doctor and clarify your doubts!
Should I Fast Before a Blood Test?
Most blood tests require us to come with an empty stomach on the day of testing. This means that our last meal ought to be at least 12 hours prior to our blood test.
Do’s and Don’ts Before the Blood Test
Don’t
- Drink caffeine/ coffee the day of testing: Coffee (even black coffee) can affect our blood test results, has a dehydrating effect and may cause our doctor or nurse to struggle to find a vein to draw blood. This can be quite stressful for both parties!
- Drink sugary drinks during our period of fasting: fruit juice, tea and soda – these can affect our blood sugar levels.
- Drink alcohol 24 hours prior to the blood test. Alcohol can remain in our bloodstream for 2-3 days, which may affect our liver function test results.
- Smoke.
- Chew gum – even sugar-free gum can affect our blood results.
Do
- Continue to take your medications: unless our doctor has specifically told us to refrain from them!
- Arrive early for the doctor’s appointment. This can ensure that we have enough time to park and not rush!
- Stay hydrated while fasting. Pure water is allowed.
Health is Wealth
Your health is of utmost importance to us. Here at Kantha Medical Group, we are committed to providing you with the best healthcare.
We offer comprehensive blood screening packages to assess your health. Every person deserves a right to proper healthcare and adequate education on health.
Make an appointment with us today! Blood screening promotion ends 31st January 2023.
References
- Thrombocytopenia https://www.mayoclinic.org/diseases-conditions/thrombocytopenia/symptoms-causes/syc-20378293
- Haemoglobin and iron: information for blood donors https://www.ncbi.nlm.nih.gov/books/NBK310577/
- Chronic kidney disease https://www.mayoclinic.org/diseases-conditions/chronic-kidney-disease/symptoms-causes/syc-20354521
- Acute kidney failure https://www.mayoclinic.org/diseases-conditions/kidney-failure/symptoms-causes/syc-20369048
- Physiology, Liver https://www.ncbi.nlm.nih.gov/books/NBK535438/
- Liver: Anatomy and Functions https://www.hopkinsmedicine.org/health/conditions-and-diseases/liver-anatomy-and-functions
- Diabetes Mellitus Laboratory Tests http://www.myhealth.gov.my/en/diabetes-mellitus-laboratory-tests/
- Adult Health Maintenance Guidelines https://dchr.dc.gov/sites/default/files/dc/sites/dchr/publication/attachments/Adult%20Health%20Maintenance%20Guidelines_dchr.pdf
