How to Read Your Blood Test Results: Cholesterol, Blood Sugar, and Blood Pressure

Quick Summary

Routine blood tests measure essential parameters for cardiovascular and metabolic health
LDL cholesterol, fasting blood glucose, and blood pressure are the three key metrics to monitor
"Normal values" depend heavily on your age, sex, and individual risk factors
A single out-of-range number is not a diagnosis: it always requires clinical context from a physician

Why Understanding Your Test Results Matters

Every year, millions of people look at their blood test report for a few seconds and then tuck it away in a drawer. Yet, those numbers tell a critical story about our well-being — often long before any physical symptoms show up.

This is not about becoming your own doctor. It is about understanding your metrics well enough to ask your healthcare provider the right questions, recognize when a result needs attention, and see how your daily lifestyle choices directly affect your numbers.

Cholesterol: One Name, Multiple Types

When "cholesterol" appears on a lab report, it actually represents several distinct markers. Let's break them down.

Total Cholesterol

This is the sum total of all cholesterol forms in your bloodstream. A desirable value is under 200 mg/dL. Values between 200 and 239 mg/dL are considered "borderline high"; anything above 240 mg/dL indicates hypercholesterolemia. However, total cholesterol alone is not very informative — what truly matters is the breakdown.

LDL Cholesterol — The "Bad" Kind

LDL stands for Low-Density Lipoprotein. It carries cholesterol from the liver to the cells, but when there is an excess, it deposits into the arterial walls, forming atherosclerotic plaques that can lead to heart attacks and strokes.

LDL (mg/dL)	Classification
< 100	Optimal
100 – 129	Near optimal
130 – 159	Borderline high
160 – 189	High
≥ 190	Very high

Note: If you have established cardiovascular disease, diabetes, or a high overall cardiovascular risk, your target LDL level will be much lower (under 70 or even 55 mg/dL). Your doctor will determine your personalized target.

HDL Cholesterol — The "Good" Kind

HDL (High-Density Lipoprotein) sweeps excess cholesterol away from tissues and returns it to the liver for excretion. The higher your HDL, the better. Values below 40 mg/dL for men and below 50 mg/dL for women are considered major cardiovascular risk factors.

Non-HDL Cholesterol

Many modern lab reports include Non-HDL cholesterol (Total Cholesterol minus HDL). The 2021 ESC guidelines highlight this marker as a highly accurate cardiovascular predictor because it accounts for VLDL and other atherogenic particles. An optimal target is < 130 mg/dL.

Check your metrics

Calculate Your Cardiovascular Risk Score

Input your cholesterol, HDL, and blood pressure into the SCORE2/ASCVD calculator

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Triglycerides

Triglycerides are a type of fat in the blood derived from the food we eat and synthesized by the liver. Normal values are under 150 mg/dL. Levels between 150 and 199 mg/dL are "borderline high", and levels above 200 mg/dL require clinical attention. Spikes in triglycerides are heavily driven by simple sugars, alcohol, refined carbohydrates, and physical inactivity — rather than dietary fats alone.

Blood Glucose

Blood glucose measures the concentration of sugar in your bloodstream. It is standardly measured after a fasting window of at least 8 hours.

Fasting Blood Glucose (mg/dL)	Interpretation
< 100	Normal
100 – 125	Prediabetes (Impaired Fasting Glucose)
≥ 126 (Confirmed on two separate occasions)	Diabetes

A fasting glucose reading between 100 and 125 mg/dL is not diabetes, but it serves as an early warning sign that your carbohydrate metabolism is changing. With timely lifestyle interventions, it is often completely reversible.

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Blood Pressure

Blood pressure is measured in mmHg and is reported as two numbers: systolic (the top number, indicating the pressure when the heart beats) and diastolic (the bottom number, indicating the pressure when the heart rests between beats).

Blood Pressure (mmHg)	ESC 2018 Classification
< 120 / < 80	Optimal
120–129 / 80–84	Normal
130–139 / 85–89	High-normal
140–159 / 90–99	Grade 1 hypertension
160–179 / 100–109	Grade 2 hypertension
≥ 180 / ≥ 110	Grade 3 hypertension

Blood pressure fluctuates naturally throughout the day based on physical stress and emotion. A single elevated reading is not enough to diagnose hypertension. Your physician will look at multiple measurements taken across different points in time.

How often should I get routine blood work done?

In the absence of existing health risks, once a year is generally standard for adults over 40. For younger, healthy individuals, once every 2 to 3 years is typically sufficient. Your primary care physician will tell you the best frequency for your health profile.

Do I need to fast before my blood draw?

Yes. Most standard metabolic panels (cholesterol, glucose, triglycerides) require a fasting window of 8 to 12 hours. Drinking plain water is perfectly fine. You should strictly avoid alcohol for 24 hours prior to the test. If your doctor has ordered a creatinine test, avoid heavy weightlifting or intense workouts the day before.

One of my metrics came back flagged as out-of-range. Should I panic?

A single value that falls slightly outside the standard laboratory reference range rarely signifies an emergency. Before worrying, discuss the results with your doctor, who can interpret the flag within your full clinical picture and determine if a follow-up test is necessary.

Williams B et al. 2018 ESC/ESH Guidelines for the management of arterial hypertension. Eur Heart J. 2018;39(33):3021-3104.

Mach F et al. 2019 ESC/EAS Guidelines for the management of dyslipidaemias. Eur Heart J. 2020;41(1):111-188.