What does meaningful preventive screening actually look like?

What does standard preventive screening cover?

Standard preventive screening covers blood pressure, a basic cholesterol panel, fasting glucose, and cancer screening for the colon, breast, cervix and skin, plus the lungs in people with a heavy smoking history. Universally recommended screening for most adults:

• Blood pressure (every visit)
• Basic lipid panel (LDL-C, HDL, triglycerides, total cholesterol)
• Fasting glucose
• Colon cancer screening: colonoscopy starting at 45 in most current guidelines, with stool-based testing as alternatives
• Breast cancer screening for women: mammography starting at 40 to 50 depending on guideline
• Cervical cancer screening: Pap smear and HPV testing
• Lung cancer screening: low-dose lung CT for high-risk smokers
• Skin examinations

These programs catch many cancers early and identify some cardiovascular and metabolic disease, but they leave large categories of risk uncovered.

What's missing from standard screening that catches risk earlier?

The markers most often missing from a standard panel are ApoB, Lp(a), fasting insulin, hs-CRP, homocysteine, a full thyroid panel, vitamin D and B12, a coronary artery calcium score and a body composition scan. Several markers catch risk decades before standard screening would identify a problem:

• ApoB. Apolipoprotein B counts the actual atherogenic particles in circulation, more accurate than LDL-C alone for cardiovascular risk. Should be measured in any cardiovascular risk assessment
• Lp(a). Lipoprotein(a). A genetically-determined risk factor for cardiovascular disease and aortic stenosis, affecting roughly 20% of the population at clinically significant levels. The 2024 National Lipid Association Update strongly endorses one-time lifetime Lp(a) screening [PMID: 38565461]. Worth measuring once because the result doesn't change
• Fasting insulin and HOMA-IR. Catches insulin resistance years before glucose abnormalities. Most adult metabolic dysfunction begins here
• hs-CRP. A general inflammation marker associated with cardiovascular and other disease risk
• Homocysteine. Associated with cardiovascular risk, cognitive risk, and thrombotic risk. Often responsive to B vitamin optimization
• Comprehensive thyroid panel. TSH alone misses much of what matters
• Vitamin D, B12 with methylmalonic acid. Common deficiencies that contribute to multiple disease processes
• Coronary artery calcium (CAC) score. A CT-based test that visualizes calcified plaque in coronary arteries. CAC of 0 indicates very low cardiovascular risk; elevated CAC dramatically changes risk stratification
• Body composition (DEXA scan). Assesses lean mass, fat distribution, and bone density in a single test

What is a coronary artery calcium scan, and when is it useful?

A coronary artery calcium (CAC) scan is a low-radiation CT scan that measures calcified plaque in the coronary arteries. The result is a numerical score:

• CAC of 0: No detectable calcified plaque. Very low cardiovascular event risk in the next 10 years
• 1-100: Mild
• 101-400: Moderate, with significantly elevated risk
• 400+: Significant disease, with high risk

CAC scoring is most useful for adults in their 40s and 50s with intermediate cardiovascular risk where the decision to start preventive medications (like statins) isn't obvious. A CAC of 0 in someone with elevated cholesterol can support deferring medication; a high CAC supports more aggressive treatment.

The radiation dose is low (similar to a mammogram). The cost is moderate (typically $100-400 in the US, often not covered by insurance for primary prevention).

How does family history shape screening priorities?

Family history moves screening earlier and makes it more targeted, because a close relative's colon cancer, early heart disease, breast or ovarian cancer, or dementia each points to specific tests and an earlier start. Family history is one of the most useful inputs for personalizing screening:

• First-degree relative with colon cancer often means colonoscopy should start 10 years earlier than the relative's age at diagnosis
• Family history of cardiovascular disease at young ages elevates the importance of advanced lipid testing, Lp(a), and CAC scoring
• Family history of breast or ovarian cancer raises consideration of BRCA testing and earlier or more frequent imaging
• Family history of dementia, especially early-onset raises consideration of ApoE genotyping and aggressive management of modifiable cognitive risk factors
• Family history of multiple cancers, young-onset cancers, or specific cancer patterns suggests evaluation for hereditary cancer syndromes

Family history isn't deterministic, but it changes the math on which screenings to prioritize and when.

What does genetic risk testing add?

Genetic risk testing adds what no blood panel or scan can show: inherited risk for certain cancers, heart disease and Alzheimer's disease, and how the body handles some medications. Genetic risk testing has become accessible and affordable. Targeted panels assess:

• Hereditary cancer risk. BRCA1/2 (breast, ovarian, prostate, pancreatic), Lynch syndrome (colorectal, endometrial, ovarian), Li-Fraumeni syndrome, multi-gene panels
• Cardiovascular genetic risk. Familial hypercholesterolemia, Lp(a) genotype
• ApoE genotype. Alzheimer's risk stratification, with ε4 carriers facing higher risk and ε2 carriers having lower risk
• Pharmacogenomic information. How the body metabolizes various medications

The results don't determine outcomes, but they guide screening intensity and intervention strategy. A patient with a BRCA mutation needs different screening than a patient without. A patient who is homozygous for ApoE4 has reason to be more aggressive about modifiable cognitive risk factors.

What screening matters at different life stages?

Screening priorities shift by decade: baselines in the 30s, advanced cardiovascular and hormonal assessment in the 40s, fuller cardiovascular, cancer, cognitive and bone evaluation in the 50s, and function, muscle and medication review from the 60s on. Different decades emphasize different priorities:

• 30s. Baseline metabolic and cardiovascular markers, comprehensive thyroid, hormone baseline, body composition, family history-driven genetic testing if relevant. The decade where prevention starts mattering and where most adults are still healthy
• 40s. Add cardiovascular advanced screening (ApoB, Lp(a), possibly CAC scoring), enhanced cancer screening per family history, perimenopausal evaluation in women, comprehensive hormonal assessment in men. The decade where early dysfunction often appears
• 50s. Comprehensive cardiovascular assessment with CAC, cancer screening per guidelines plus considerations like multi-cancer early detection, cognitive risk assessment with ApoE if not done, bone density baseline, comprehensive hormonal evaluation. The decade where intervention has the largest cumulative benefit
• 60s and beyond. Continued comprehensive screening, fall risk assessment, sarcopenia assessment, cognitive assessment, comprehensive medication review, adjustment of intervention strategies based on accumulated risk profile

Is comprehensive screening worth the cost?

The cost-benefit calculation tends to be favorable. Early detection of cardiovascular disease, cancer, or metabolic dysfunction prevents disease that costs orders of magnitude more in treatment, suffering, and lost healthspan.

A comprehensive baseline assessment in the 30s, 40s, or 50s is among the more cost-effective interventions in medicine, particularly when guided by individual risk profile and family history. Many of the advanced markers (ApoB, fasting insulin, hs-CRP) cost relatively little compared to standard panels.

The bigger barrier is usually not cost but access: most insurance-based primary care doesn't routinely run these panels, so patients have to know to ask, find a clinician who orders them, or pay out of pocket.

What do home blood pressure readings tell you, and how are they taken properly?

Home readings show what blood pressure does across ordinary days, which is a truer picture than a single measurement in a clinic, and they are only as good as the technique behind them. Pressure measured outside the office often differs considerably from the office number, and higher out-of-office pressure is tied to higher cardiovascular risk independent of the office reading [PMID: 32567342]. A home log is also how two common mismatches come to light: white-coat hypertension, high in the office and normal at home, and masked hypertension, normal in the office and high at home, the second of which carries substantially more risk [PMID: 30827125]. The American Heart Association's statement on blood pressure measurement sets out the technique that makes a home number trustworthy [PMID: 30827125]:

• The device. A validated automatic monitor with an upper-arm cuff sized to the arm; wrist and finger devices are less reliable
• Before measuring. An empty bladder, then at least five minutes of sitting quietly, without talking or using a phone
• Position. Back supported, both feet flat on the floor, legs uncrossed, the cuff on a bare upper arm, and the arm resting on a table
• How many. Two readings at least a minute apart in the morning, before any blood pressure medication, and two more in the evening before bed
• How long. Ideally seven days in a row and at least three, with the average of all the readings as the result; some guidelines leave out the first day

One reading says very little, because pressure moves with sleep, stress, pain, caffeine, alcohol and the time of day, and individual readings can swing widely within a single week. The average over several days is the number that counts, and under current US guidance an average of 130 over 80 or higher is considered high at home, the same figure used in the office [PMID: 30827125]. A physician reads the log for more than the average: whether mornings run higher than evenings, how far the home and office numbers sit apart, whether the monitor is validated and the cuff fits, and what else is in the picture, such as snoring and poor sleep, alcohol, salt, some pain relievers and decongestants, kidney function and family history. That review decides whether the next step is lifestyle change, a 24-hour ambulatory monitor to settle an unclear picture, or blood pressure medication, and the same log later shows whether the change is working.

A very high reading, commonly taken to mean around 180 over 120 or above, together with chest pain, trouble breathing, a severe headache, confusion, vision changes, or sudden weakness or numbness is an emergency: call 911 or go to the nearest emergency department [PMID: 29939523]. The same number without symptoms is not the same emergency: it is usually rechecked after a few minutes of quiet rest and, if it holds, brought to a physician promptly.

The deeper picture

Standard preventive care is the floor, not the ceiling. A comprehensive baseline assessment in your 30s, 40s, or 50s, with appropriate advanced markers and personalized to your risk profile, creates the map for everything that follows. The earlier the assessment, the more decades of compounding benefit. Extend builds this kind of comprehensive prevention into standard care.