Health guide · For research & reference only
How to Read Your Blood Test Results (LDL, HDL, Glucose Explained)
Short answer: your blood test report compares your numbers to a reference range, and "normal" depends on your age, sex, lab and medical history — so read the ranges on YOUR report, not a generic chart, and confirm with the clinician who ordered the tests.
This guide explains the most common results in plain English: cholesterol (LDL/HDL), glucose, blood pressure basics, and the questions worth asking your doctor. It is educational information for research and reference only — it is not a diagnosis.
Start with the reference range on your own report
Every lab prints a reference range next to your value (for example "130 mg/dL (range 0–99)"). A result outside the range is a flag for a conversation with your clinician — not a diagnosis by itself. Two important caveats:
- Ranges differ between laboratories, testing methods, and countries (mg/dL vs mmol/L).
- "Normal for the population" is not the same as "optimal for you" — target goals change with your age, pregnancy, diabetes, heart disease or other conditions.
LDL ("bad") cholesterol — what it means
LDL carries cholesterol to your tissues; high levels can build up plaque in artery walls over time (atherosclerosis), raising long-term risk of heart attack and stroke. General adult targets used in the U.S. (confirm with your lab and doctor):
| Category | LDL (mg/dL) |
|---|---|
| Optimal | Less than 100 |
| Near optimal / borderline high | 100–129 |
| High | 130–159 |
| Very high | 160 and above |
If you already have heart disease, diabetes or high risk, your doctor may target lower LDL goals. High LDL itself rarely causes symptoms — it is found by a blood test.
HDL ("good") cholesterol
HDL helps remove cholesterol from the bloodstream. Generally, higher is better (roughly 60 mg/dL and above is considered protective; below 40 for men / 50 for women is a risk factor). Total cholesterol and triglycerides complete the picture — don't read any single number alone.
Fasting blood glucose — the basics
- Normal fasting glucose (after 8+ hours without food): roughly 70–99 mg/dL (3.9–5.5 mmol/L).
- 100–125 mg/dL is often called *prediabetes* (impaired fasting glucose).
- 126 mg/dL or higher on two separate tests is the classic threshold a clinician uses when evaluating diabetes.
A single high reading needs confirmation and context (stress, illness, medication, what you ate). Never self-diagnose from one number.
A1c — the 3-month average
A1c estimates your average blood sugar over ~3 months: below 5.7% is normal range, 5.7–6.4% indicates prediabetes risk, 6.5%+ on repeat testing suggests diabetes. Interpretation always belongs to a clinician.
Other common items on a panel
- Triglycerides: <150 mg/dL is generally desirable; measured fasting.
- Blood pressure (often checked with labs): normal is generally <120/80 mmHg — see our article on blood pressure numbers explained.
- Liver/kidney markers (ALT, AST, creatinine, eGFR): each has its own range; mild single elevations are common and often need a repeat test.
- White/red blood cells: variations happen with infections, stress and altitude — context matters.
What to do with your results
1. Look at your reference ranges, not internet charts. 2. Note anything flagged high/low and the exact number. 3. Bring the report (or photo) to your clinician and ask: - "Which of these should I worry about most?" - "What is the target for someone like me?" - "Do I need a repeat test, and when?" 4. Ask what lifestyle changes or medications (if any) are appropriate for YOUR history — never start or stop medication based on a search.
Frequently asked questions
Can an AI chat explain my blood test results?
It can explain what the tests and terms generally mean, and help you prepare questions — but it cannot interpret your individual results. BuddyDoc does exactly this, clearly labeled as research and reference only.
Why is my result high when I feel fine?
Many conditions (like high cholesterol or early glucose issues) cause no symptoms. That is why routine panels exist — and why follow-up with a clinician matters.
Do ranges differ between labs?
Yes. Always compare against the range printed on your own report.
mg/dL or mmol/L — which is right?
Both are used; the U.S. commonly uses mg/dL, many other countries mmol/L. They are different units for the same value.
What if my result is out of range?
It is a reason to ask your doctor — not to panic and not to self-diagnose.
More resources
- American Heart Association — cholesterol & blood pressure education: heart.org
- CDC — diabetes & prediabetes basics: cdc.gov/diabetes
- National Library of Medicine (MedlinePlus): medlineplus.gov/lab-tests
*BuddyDoc provides general health information for research and reference only. It does not provide medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider about a medical condition. In an emergency, call your local emergency number. → Ask BuddyDoc free for 7 days: vital24.vip/app*