Dr. Onn here.
A general educational guide to common blood tests.
Why Blood Tests Matter
- →Many health problems develop silently, without symptoms.
- →Blood tests can detect heart disease, diabetes, kidney issues and inflammation early.
- →Understanding your numbers helps you make better decisions about diet and lifestyle.
- →It reduces confusion and prevents relying on "doctor said okay" without knowing what it means.
- →Tracking your results yearly shows whether your health is improving or worsening.
This guide shows you what to check, what the numbers mean, and when to take action.
Yearly Blood Test Checklist
A quick list of tests to request during your annual health check.
Essential Tests
- →Lipid Profile (LDL, HDL, Triglycerides)
- →HbA1c (3-month average blood sugar)
- →Fasting Blood Glucose
- →Kidney Function (Creatinine, eGFR)
- →Liver Function (ALT, AST)
- →Full Blood Count (FBC)
- →hs-CRP (inflammation marker)
Optional But Useful Tests
- →Thyroid Panel (TSH)
- →Vitamin D (25-OH Vitamin D)
- →Uric Acid
- →Iron Studies (if prone to low energy or anaemia)
Understanding Your Cholesterol Panel
Your cholesterol profile helps identify your long-term risk of heart disease.
LDL (Low-Density Lipoprotein)
What it means: Often called "bad cholesterol," this type contributes to plaque buildup in the arteries.
LDL is produced by our liver, so it isn't necessarily bad.
However, LDL can change from neutral to harmful depending on our lifestyle. It can become small and dense (sdLDL), get affected by high blood sugar (glycated LDL), or turn more aggressive and inflammatory due to smoking and vaping.
Discuss with your doctor what your LDL target should be, as this depends on your current health status and whether you have conditions such as heart disease or stroke.
HDL (High-Density Lipoprotein)
What it means: The "good cholesterol" that helps remove excess cholesterol from the bloodstream.
Healthy levels:
- →Men: >1.0 mmol/L
- →Women: >1.2 mmol/L
If low: higher cardiovascular risk, even if LDL is normal.
Triglycerides
What it means: A type of fat in the blood. Often increases with diets high in sugar, refined carbs, sweet drinks, and overeating.
Normal ranges:
- →<1.7 mmol/L = normal
- →1.7-2.2 mmol/L = borderline
- →>2.3 mmol/L = high
- →>5.0 mmol/L = very high (needs urgent attention)
If high: suggests metabolic issues or insulin resistance.
Understanding Your Diabetes Markers
These tests help you understand your long-term and short-term blood sugar levels, as well as your risk for diabetes and metabolic disease.
HbA1c (Glycated Hemoglobin)
What it means: HbA1c reflects your average blood sugar level over the past 3 months. It is the most reliable long-term marker of glucose control. The lower the better.
Normal ranges:
- →<5.3% = Good
- →<5.7% = normal
- →5.7-6.4% = prediabetes
- →≥6.5% = diabetes
- →>7% = poor long-term control
If high:
- →Increased long-term cardiovascular risk
- →Higher risk of diabetes complications
- →Indicates sustained high blood sugar
- →Often associated with insulin resistance
What affects it:
- →Diet (carbs, sugars)
- →Weight and metabolism
- →Sleep quality
- →Stress
- →Certain medications (e.g., steroids)
Fasting Blood Glucose
What it means: Your blood sugar level after 8-12 hours of fasting. Measures short-term glucose status.
Normal ranges:
- →4.0-5.5 mmol/L = normal
- →5.6-6.9 mmol/L = prediabetes
- →≥7.0 mmol/L = diabetes
If high:
- →Early sign of impaired glucose control
- →Often linked with insulin resistance
- →Indicates increased metabolic and cardiovascular risk
What can affect the reading:
- →Eating or drinking (non-water) during the fasting period
- →Stress or lack of sleep
- →Acute illness
- →Medications
- →Excessive sugar or carbs the night before
Red Flags (Recommend Medical Review)
- →HbA1c ≥7%
- →Fasting glucose ≥7.0 mmol/L
- →Rapid changes compared to your last test
- →Consistently rising numbers over time
Understanding Kidney & Liver Function Tests
These tests help monitor the health of two major organs that affect metabolism, blood pressure, and long-term heart risk.
Kidney Functions
Creatinine
What it means: Creatinine is a waste product from muscles. Kidneys remove it from the blood. High levels suggest reduced kidney filtering function.
Typical ranges (varies slightly by lab and muscle mass):
- →Men: ~60-110 µmol/L
- →Women: ~45-90 µmol/L
If high:
- →Possible kidney impairment
- →Can also rise temporarily from dehydration, exercise, or high protein intake
eGFR (Estimated Glomerular Filtration Rate)
What it means: A calculation showing how well your kidneys filter waste.
General interpretation:
- →>90 = normal
- →60-89 = mild reduction
- →<60 = chronic kidney disease (CKD)
- →<30 = severe CKD
- →<15 = kidney failure
Note: eGFR naturally decreases with age. This can be normal depending on context.
Liver Function
ALT (Alanine Aminotransferase)
What it means: An enzyme in liver cells. High levels indicate liver inflammation or stress.
Typical normal range: <40 U/L (varies by lab).
If high:
- →Possible fatty liver
- →Alcohol effect
- →Medication reaction
- →Viral or metabolic liver conditions
AST (Aspartate Aminotransferase)
What it means: Another liver enzyme. Often elevated together with ALT.
Typical normal range: <40 U/L.
If high:
- →Similar causes as ALT
- →If AST is much higher than ALT → may suggest alcohol-related effects or muscle injury
Other Important Tests
These additional tests help give a fuller picture of your overall health, immunity, inflammation, and metabolic status.
Full Blood Count (FBC)
- →Hemoglobin (Hb): Oxygen-carrying protein in red blood cells.
- →White Blood Cells (WBC): Reflects immune system activity.
- →Platelets: Cells that help with blood clotting.
hs-CRP (High-Sensitivity C-Reactive Protein)
What it means: A marker of inflammation in the body. Useful for assessing cardiovascular and metabolic risk.
Uric Acid
What it means: Waste product linked to gout, inflammation, kidney function, and metabolic health.
Normal range:
- →Men: <420 µmol/L
- →Women: <360 µmol/L
If high:
- →Risk of gout
- →Higher metabolic and cardiovascular risk
- →Often linked to diet and lifestyle
Perkara Utama
- 1Request the essential tests at your yearly check: lipid profile, HbA1c, fasting blood glucose, kidney and liver function, full blood count, and hs-CRP.
- 2HbA1c reflects your average blood sugar over the past 3 months and is the most reliable long-term marker of glucose control.
- 3Red flags that need a medical review: HbA1c of 7% or more, fasting glucose of 7.0 mmol/L or more, or consistently rising numbers over time.
Penulis
Assoc. Prof. Dr. Onn Akbar Ali
Senior Consultant Interventional Cardiologist · KPJ Ampang Puteri & KPJ Kajang Specialist Hospitals · MMC 57710 · NSR 129274
Kenali Dr. Onn ›Artikel ini adalah untuk tujuan pendidikan sahaja dan bukan nasihat perubatan peribadi. This article is for educational purposes only and does not constitute personal medical advice.