Getting a blood test is one thing; understanding the results is another. A laboratory report may contain abbreviations, numbers and reference ranges that can be difficult to understand if you are not familiar with medical testing.
Blood test results can provide useful information about blood cells, blood sugar, cholesterol, kidney function, liver health, inflammation and other aspects of the body. However, an individual result should not usually be interpreted on its own.
This guide explains some of the common blood test values you may see on a laboratory report and what they generally indicate.
What Is a Blood Test Result?
A blood test result is a measurement obtained from analysing a blood sample in a laboratory.
Depending on the test requested, the laboratory may measure the number of cells in your blood, the concentration of a substance, or the activity of a particular enzyme or other marker.
Your report may show:
- The name of the test
- Your result
- The unit of measurement
- A reference range
- Sometimes a flag showing that a result is above or below the laboratory's reference range
The meaning of the result depends on the specific test and the circumstances in which it was performed.
If you need laboratory testing, explore AnalysisAfrica's medical testing services to learn more about available tests.
What Is a Reference Range?
A reference range is a range of results that a laboratory uses as a comparison when reporting a particular test.
Reference ranges can differ between laboratories because they may use different testing methods, equipment and reference populations.
This is why you should use the reference range printed on your own laboratory report rather than comparing your number with a random range found online.
A result outside the reference range does not automatically mean that you have a disease. Similarly, a result within the range does not guarantee that everything is normal.
Healthcare professionals consider the result together with your symptoms, medical history and other findings.
Understanding Common Blood Test Values
1. Haemoglobin (Hb)
Haemoglobin is a protein in red blood cells that helps carry oxygen around the body.
Your blood test report may show your haemoglobin level in units such as g/dL.
A lower-than-expected haemoglobin level may occur with anaemia and other conditions, while an elevated level can have several possible causes.
Haemoglobin results are usually interpreted alongside other blood measurements.
2. Red Blood Cell Count (RBC)
The red blood cell count indicates the number of red blood cells in a given volume of blood.
Red blood cells carry oxygen from the lungs to tissues throughout the body.
An unusually high or low RBC count can have different causes, so it is normally considered together with haemoglobin, haematocrit and other blood count results.
3. White Blood Cell Count (WBC)
White blood cells are involved in the body's immune response.
The WBC result indicates the number of white blood cells in the blood.
A high or low result may be associated with infections, inflammation, medications and other conditions. More information can often be obtained by looking at the different types of white blood cells.
4. Platelet Count
Platelets play an important role in blood clotting.
The platelet count measures the number of platelets in the blood.
A platelet count that is too low or too high can have several possible explanations, which is why the result should be interpreted in context.
Understanding Blood Sugar Results
5. Fasting Blood Glucose
A fasting blood glucose test measures blood sugar after a specified period without eating.
It can be used to screen for or monitor diabetes and other problems involving blood glucose regulation.
The interpretation depends on the measurement unit and the reference or diagnostic criteria being used.
6. Random Blood Glucose
A random blood glucose test measures blood sugar at a particular time without necessarily requiring fasting.
The result can be affected by when you last ate, what you ate, medications and other factors.
For this reason, the timing of the test and the circumstances surrounding it are important when interpreting the result.
7. HbA1c
HbA1c provides information about average blood glucose levels over approximately the previous two to three months.
Unlike a single blood glucose measurement, HbA1c gives a longer-term picture of blood sugar control.
It is commonly used in diabetes screening and monitoring.
Understanding Cholesterol Results
8. Total Cholesterol
Total cholesterol represents the overall amount of cholesterol measured in the blood.
It is usually considered together with other lipid measurements rather than being interpreted alone.
9. LDL Cholesterol
LDL is commonly referred to as low-density lipoprotein cholesterol.
Higher LDL levels can be associated with increased cardiovascular risk, depending on the individual's overall health and other risk factors.
10. HDL Cholesterol
HDL stands for high-density lipoprotein.
HDL is involved in transporting cholesterol through the bloodstream, and its level is considered alongside other lipid measurements when assessing cardiovascular health.
11. Triglycerides
Triglycerides are another type of fat found in the blood.
High triglyceride levels can occur for several reasons, including dietary factors, certain health conditions and metabolic disorders.
A lipid profile usually provides a more complete picture than looking at triglycerides alone.
Understanding Kidney Function Results
12. Creatinine
Creatinine is a waste product produced by normal muscle metabolism and removed from the body through the kidneys.
Blood creatinine levels can provide information about kidney function.
However, creatinine can also be influenced by factors such as muscle mass and other circumstances, so it should not be interpreted by itself.
13. Urea
Urea is another waste product that is removed from the body through the kidneys.
A blood urea result can be affected by kidney function, hydration, diet and other factors.
14. eGFR
Estimated glomerular filtration rate, commonly abbreviated as eGFR, provides an estimate of how effectively the kidneys are filtering the blood.
It is generally calculated using creatinine and other information.
Healthcare professionals may use eGFR alongside other kidney tests to assess kidney function.
Understanding Liver Test Results
15. ALT
Alanine aminotransferase (ALT) is an enzyme found mainly in the liver.
Higher-than-expected ALT levels can occur when liver cells are damaged, although there are several possible causes of an elevated result.
16. AST
Aspartate aminotransferase (AST) is another enzyme that can be measured as part of liver testing.
Unlike ALT, AST is found in several tissues, including the liver and muscles. Therefore, an elevated AST result does not necessarily indicate a liver problem by itself.
17. ALP
Alkaline phosphatase (ALP) is an enzyme associated with several tissues, particularly the liver, bile ducts and bones.
An abnormal ALP result may require additional testing to determine its possible source.
18. Bilirubin
Bilirubin is produced when red blood cells are broken down.
The liver processes bilirubin, and blood testing can help assess problems involving bilirubin metabolism, the liver or bile flow.
Higher bilirubin levels can sometimes be associated with jaundice.
Other Common Blood Test Values
19. Albumin
Albumin is a major protein produced by the liver.
Blood albumin levels can provide information that may be useful when assessing nutritional status, liver function, kidney-related protein loss and other conditions.
20. Total Protein
A total protein test measures the overall amount of certain proteins in the blood, including albumin and other proteins.
Abnormal results can have several possible causes and may require additional testing.
21. Calcium
Calcium is important for bones, muscles, nerves and other functions in the body.
A calcium blood test can be requested when healthcare professionals need to investigate problems involving calcium regulation or certain medical conditions.
22. Uric Acid
Uric acid is produced when the body breaks down substances called purines.
High uric acid levels can be associated with gout and other conditions, although an elevated result does not automatically mean that a person has gout.
23. CRP
C-reactive protein (CRP) is a marker that can increase when inflammation is present in the body.
CRP can help healthcare professionals assess inflammation, but it generally does not identify the exact cause on its own.
24. ESR
The erythrocyte sedimentation rate (ESR) is another test that can provide information about inflammation.
Like CRP, ESR is a non-specific marker. An abnormal result can occur in several different situations and needs to be interpreted alongside other information.
Why Can Blood Test Results Be Abnormal?
There are many reasons why a blood test result may fall outside a laboratory's reference range.
Possible factors include:
- Illness or infection
- Medications
- Diet
- Dehydration
- Physical activity
- Age
- Pregnancy
- Existing medical conditions
- Timing of the test
- Laboratory or sample-related factors
An abnormal result therefore needs context.
For example, a slightly abnormal result may not have the same significance for every person.
Does One Abnormal Result Mean Something Is Wrong?
Not necessarily.
A laboratory result is only one piece of information used when assessing someone's health.
A healthcare professional may consider:
- Your symptoms
- Your medical history
- Previous test results
- Physical examination
- Other laboratory tests
- Imaging or other investigations
Sometimes a test may be repeated to determine whether an unusual result persists.
Why You Should Not Compare Your Result With Someone Else's
It can be tempting to compare your blood test results with those of a friend or with numbers found on social media.
This can be misleading.
Different laboratories may use different reference ranges, and individual factors can influence results. Two people with the same numerical result may also have very different clinical circumstances.
Your laboratory report and healthcare professional's interpretation are more useful than comparing your result with someone else's.
When Should You Speak to a Healthcare Professional?
You should discuss your blood test results with a qualified healthcare professional if you do not understand them or if your report shows an abnormal result.
This is particularly important when you have symptoms or are being monitored for an existing medical condition.
Avoid starting medication, stopping medication or making major changes to your health based solely on an internet interpretation of a laboratory result.
Final Thoughts
Blood test results can provide valuable information about many aspects of health, including blood cells, blood sugar, cholesterol, kidney function, liver function and inflammation.
However, laboratory numbers should not be viewed in isolation. The reference range, reason for testing, symptoms, medical history and other results all contribute to understanding what a particular value means.
If you have recently had a blood test and are unsure about the numbers on your report, discuss the results with a qualified healthcare professional rather than trying to diagnose yourself from individual values.
For reliable laboratory testing, explore AnalysisAfrica's medical testing services. You can also visit the AnalysisAfrica blog for more guides on medical tests and laboratory analysis.
