Many of the strongest predictors of a long, healthy life are not exotic. They are ordinary numbers that a family doctor can measure or order, such as blood pressure, cholesterol particles, blood sugar, waist size and physical fitness. This guide explains which markers are worth knowing, what major health organizations consider typical healthy ranges, and which screenings to ask about at different ages.
Why a few numbers matter so much
Heart disease, stroke, type 2 diabetes and many cancers develop silently for years before symptoms appear. Biomarkers are measurable signals that help detect that risk early, when lifestyle changes or treatment are most effective. No single number defines your health. Their value comes from tracking them over time and interpreting them together with a clinician.
A useful way to think about them is in three groups:
- Cardiovascular markers: blood pressure, LDL cholesterol, ApoB and Lp(a).
- Metabolic markers: fasting glucose, HbA1c, waist circumference and BMI.
- Fitness and function markers: resting heart rate, estimated VO2 max and grip strength.
Blood pressure: the most important number many people skip
High blood pressure is one of the leading modifiable causes of heart attack, stroke, kidney disease and dementia, and it usually has no symptoms. The American Heart Association (AHA) classifies a reading below 120/80 mm Hg as normal, 120 to 129 systolic with diastolic below 80 as elevated, and 130/80 or higher as high blood pressure. Other countries use slightly different cut-offs.
A single reading in a clinic can be misleading because of stress or rushing. Home monitoring with a validated upper-arm cuff, taken seated after five minutes of rest, often gives a more accurate picture.
Cholesterol, ApoB and Lp(a)
LDL cholesterol
Low-density lipoprotein (LDL) cholesterol is a well-established cause of the plaque that builds up in arteries. For people at lower risk, an LDL below about 100 mg/dL (2.6 mmol/L) is generally considered optimal. People with existing heart disease, diabetes or other risk factors are often given lower targets. Targets depend on your overall risk.
ApoB
Apolipoprotein B (ApoB) counts the number of potentially artery-clogging particles rather than the cholesterol they carry. Because each harmful particle has one ApoB molecule, it can capture risk that LDL misses, especially in people with high triglycerides, diabetes or obesity. Canadian and European lipid guidelines recognize ApoB as an alternative or additional target, and values below about 90 mg/dL are often cited for people at lower risk, with lower goals for those at higher risk.
Lipoprotein(a)
Lp(a) is a cholesterol-carrying particle whose level is largely inherited and changes little over a lifetime. Elevated Lp(a) raises the risk of heart attack, stroke and aortic valve narrowing, even when other numbers look good. AHA and American College of Cardiology guidance treats a level of 50 mg/dL (roughly 125 nmol/L) or higher as a risk-enhancing factor. Several guidelines, including those of the Canadian Cardiovascular Society and the European Atherosclerosis Society, suggest measuring it at least once in adulthood. Knowing it can change how other risks are managed.
Blood sugar, waist size and the limits of BMI
Fasting glucose and HbA1c
The American Diabetes Association (ADA) uses these thresholds. A fasting plasma glucose below 100 mg/dL (5.6 mmol/L) is normal, 100 to 125 mg/dL suggests prediabetes, and 126 mg/dL (7.0 mmol/L) or higher on repeat testing indicates diabetes. HbA1c, which reflects average blood sugar over about three months, is considered normal below 5.7%, in the prediabetes range from 5.7% to 6.4%, and in the diabetes range at 6.5% or higher. Diabetes Canada uses 6.0% to 6.4% for prediabetes. Prediabetes is common and often reversible.
Waist circumference
Fat stored around the abdomen is more closely tied to metabolic and heart risk than overall weight. The U.S. National Heart, Lung, and Blood Institute flags higher risk at a waist above 40 inches (102 cm) for men and 35 inches (88 cm) for non-pregnant women. Lower cut-offs, such as 90 cm for men and 80 cm for women, are often used for people of South Asian, Chinese and Japanese descent.
BMI and its limits
Body mass index (weight in kilograms divided by height in metres squared) of 18.5 to 24.9 is classified as a healthy range for most adults. BMI is quick and useful at the population level, but it cannot distinguish muscle from fat or show where fat is stored, and may underestimate risk in some Asian populations and in older adults. It works best alongside waist measurement.
How do your habits add up? Get your personal estimate in 2 minutes.
Try the calculatorFitness markers: heart rate, VO2 max and grip strength
Resting heart rate
The AHA describes a normal resting heart rate for adults as 60 to 100 beats per minute. Within that range, studies have linked lower values to better cardiovascular fitness and lower mortality. Well-trained people may sit below 60 without any problem.
VO2 max
VO2 max measures how much oxygen your body can use during hard exercise and is the gold-standard measure of cardiorespiratory fitness. In large observational studies, people in the lowest fitness categories have markedly higher death rates than those in the highest, and a 2016 AHA scientific statement argued that fitness should be assessed routinely in clinical practice. Lab testing is most accurate; walking tests and wearables give estimates. Compare against your own past results and age-based norms. Fitness responds to training at almost any age.
Grip strength
Hand grip strength, measured with a simple dynamometer, is a quick proxy for overall muscle strength. Low grip strength is associated with disability, falls and higher mortality. The European Working Group on Sarcopenia in Older People uses values below 27 kg for men and below 16 kg for women as a signal of low strength warranting further assessment.
Summary table of key markers
Ranges below are general reference points from major organizations for adults. Confirm your personal targets with your clinician.
| Marker | Why it matters | Typical target or healthy range |
|---|---|---|
| Blood pressure | Major driver of stroke, heart attack, kidney disease and dementia | Below 120/80 mm Hg is normal (AHA) |
| LDL cholesterol | Causes arterial plaque | Below about 100 mg/dL (2.6 mmol/L) for lower-risk adults; lower if higher risk |
| ApoB | Counts harmful lipoprotein particles | Often below about 90 mg/dL for lower-risk adults; lower if higher risk |
| Lp(a) | Inherited risk factor for heart disease and valve disease | Below 50 mg/dL (about 125 nmol/L); test at least once |
| Fasting glucose | Screens for prediabetes and diabetes | Below 100 mg/dL (5.6 mmol/L) (ADA) |
| HbA1c | Average blood sugar over about 3 months | Below 5.7% (ADA) |
| Waist circumference | Reflects abdominal fat and metabolic risk | Men 40 in (102 cm) or less, women 35 in (88 cm) or less; lower for some Asian populations |
| BMI | Quick screen for weight-related risk | 18.5 to 24.9, interpreted with waist size |
| Resting heart rate | Reflects heart fitness and autonomic health | 60 to 100 bpm; lower within range often reflects fitness |
| VO2 max (estimate) | Strong predictor of overall mortality | Compare with age and sex norms; higher is better |
| Grip strength | Proxy for overall strength and frailty risk | At or above 27 kg (men) and 16 kg (women) (EWGSOP2) |
Screening schedules to ask about
Screening recommendations vary by country and change as evidence evolves. The U.S. Preventive Services Task Force (USPSTF) recommendations below are a common reference; your doctor will tailor them.
- Blood pressure: adults 18 and older; yearly from age 40 or if at higher risk, and every 3 to 5 years for younger adults with normal readings.
- Prediabetes and type 2 diabetes: adults aged 35 to 70 with overweight or obesity, and earlier for those with other risk factors.
- Cholesterol: the AHA suggests checking every 4 to 6 years from age 20 for adults at low risk, and more often with risk factors.
- Colorectal cancer: adults 45 to 75, using one of several test options.
- Breast cancer: mammography every two years for women 40 to 74.
- Cervical cancer: people with a cervix aged 21 to 65, with interval depending on test type.
- Lung cancer: yearly low-dose CT for adults 50 to 80 with a significant smoking history who currently smoke or quit within the past 15 years.
- Osteoporosis: women 65 and older, and younger postmenopausal women at increased risk.
- Prostate cancer: men 55 to 69 should make an individual decision about PSA testing with their clinician.
A caution on direct-to-consumer tests and biological age clocks
Companies now sell large blood panels, full-body scans and "biological age" tests directly to consumers. Keep these downsides in mind.
- More tests mean more false alarms. Testing many markers in healthy people raises the chance of borderline results, anxiety and unnecessary follow-up.
- Results need context. A number without your history, medications and physical exam can be misinterpreted in either direction.
- Biological age clocks are research tools. Epigenetic and other "aging clocks" are an active area of science, but they are not validated for making medical decisions. Results vary between companies and repeat samples, and there is no proof that lowering a score extends life.
- Whole-body imaging in people without symptoms is not recommended by major medical organizations because of incidental findings and, for CT, radiation exposure.
If you do use a consumer test, share the results with your doctor rather than acting on them alone.
Frequently asked questions
How often should I get blood work done?
It depends on your age, risk factors and existing conditions. Your clinician can set a schedule that fits you.
Is ApoB better than LDL cholesterol?
ApoB can be a more accurate measure of risk in some people, especially those with diabetes, high triglycerides or obesity, because it counts particles directly. LDL remains a valid and widely used marker.
Why test Lp(a) only once?
Lp(a) levels are mostly determined by genetics and stay fairly stable through adult life. One measurement is usually enough to know whether you carry this inherited risk.
Are smartwatch VO2 max estimates accurate?
Wearable estimates can be reasonably useful for tracking trends over time, but they can differ from laboratory measurements by a meaningful margin. Use them to track trends.
Should I take a biological age test?
These tests are interesting but not yet validated for guiding health decisions. Well-established measures such as blood pressure, lipids, blood sugar and fitness are far more useful.
Sources and further reading
- American Heart Association – Blood pressure, cholesterol and heart health
- American Diabetes Association – Diagnosis and prediabetes
- U.S. Preventive Services Task Force – Screening recommendations
- National Heart, Lung, and Blood Institute – Heart and metabolic health
- National Institute on Aging – Health and aging
- World Health Organization – Noncommunicable diseases
This article is for general information only and is not medical advice. Talk to a qualified health professional about your situation.