Your medical check-up: what to ask for, how often and what it means
Introduction
There are two common ways to get check-ups wrong, and they're opposites. One is having none until something hurts, which wastes years of margin on processes that advance silently. The other is stacking up blood tests and imaging without criteria, convinced that more data is always better, when in fact each unnecessary test multiplies the chance of an irrelevant finding that will generate anxiety and more testing.
There's a middle ground and it has a name: evidence-based screening. It means systematically looking for a few specific conditions, in the right people, at the right intervals, because finding them early changes the outcome. Not everything that can be measured is worth measuring, and not everything appearing on a commercial panel of two hundred variables provides useful information.
This article gathers in one place what appears scattered across other texts: which tests make sense to request, what each one adds and how often to repeat them. It's written so you arrive at your appointment knowing what to ask, not so you can diagnose yourself.
One caveat worth stating up front: screening recommendations vary by country, age, sex and family history, and guidelines get updated. What follows is a map to guide the conversation with your doctor, not a protocol to apply on your own.
It isn't about measuring everything. It's about measuring what changes a decision.
The 12 keys to a sensible check-up
1. Distinguish screening from diagnosis. Screening looks for a condition in someone without symptoms, hoping to find it earlier. Diagnosis investigates a symptom that already exists. Confusing them leads to ordering screening tests when symptoms are present — where they fall short — or to aggressive screening without indication.
2. Start with the basics: blood pressure. It's the best cost-benefit test in all of preventive medicine. Hypertension is common, produces no symptoms for years and its treatment demonstrably reduces heart attacks and strokes. It takes a minute to measure and is worth checking at least every one or two years in healthy adults.
3. Basic blood work: complete blood count, glucose, lipid panel, kidney and liver function. This is the standard, reasonable block for an adult. It covers anemia, blood sugar abnormalities, cardiovascular risk and the functioning of two key organs. In healthy people without risk factors, every two or three years usually suffices; with risk factors, annually.
4. Ask for ferritin if you're tired. It's the most forgotten test and the one that most often explains unexplained exhaustion. Iron stores run out before hemoglobin falls, so a normal blood count doesn't rule out deficiency. Especially relevant in women with heavy periods, endurance athletes and vegetarian diets.
5. Add TSH if the picture fits. Hypothyroidism causes fatigue, cold intolerance, constipation, dry skin and mental slowness, and it's common. TSH is cheap and widely available. There's no consensus on screening the whole asymptomatic population, but with compatible symptoms the test is clearly indicated.
6. If cardiovascular risk matters to you, ask for ApoB or non-HDL cholesterol. The standard lipid panel is informative, but particle number is more so. ApoB counts them directly; non-HDL cholesterol is calculated free from data you already have. And Lp(a) is measured once in a lifetime: it's genetic and doesn't change.
7. Consider fasting insulin if there are metabolic factors. Fasting glucose is the last indicator to become abnormal. With glucose and insulin you calculate the HOMA-IR index, which detects resistance years earlier. It isn't a population screen, but it makes a lot of sense with abdominal obesity, family history or high triglycerides.
8. Glycated hemoglobin looks at the last three months. HbA1c reflects average glucose over the past quarter, so it doesn't depend on whether you ate breakfast. It's the usual test for screening diabetes in people with risk factors and for following those who already have it.
9. Measure vitamin D only if there's a reason. Screening the whole population isn't indicated. It is indicated in people with little sun exposure, darker skin at high latitudes, obesity, malabsorption, osteoporosis or certain medications. Measuring before supplementing avoids both untreated deficiency and unnecessary supplementation.
10. Don't skip the cancer screenings that genuinely save lives. Colorectal, breast and cervical cancer have screening programs with demonstrated benefit, and every country has age-based schedules. They're among the few screenings with solid evidence of reducing mortality. If a letter arrives from your health service inviting you, that letter is worth more than any private panel.
11. Add dental and eye checks to the calendar. A dental review every six to twelve months detects periodontal disease before teeth loosen. A periodic eye examination, especially from forty onward, detects glaucoma, which advances without symptoms until visual field loss is irreversible.
12. Be wary of "complete" commercial panels. Analyzing two hundred parameters in a healthy person guarantees several will fall outside range by pure statistical chance, meaning nothing. The predictable result is anxiety, more tests and sometimes unnecessary interventions. More data isn't more information.
What to check at each stage
From 20 to 40. Blood pressure, basic blood work every two or three years, dental and eye checks, and whichever cancer screenings apply by sex and age in your country. It's also the age to learn your Lp(a) and your family history, which condition everything else.
From 40 to 60. The intervals tighten: annual or biennial blood work, more regular blood pressure monitoring, entry into colorectal cancer screening and, for women, breast screening. It's the decade when insulin resistance and dyslipidemia start showing up.
From 60 onward. Add bone density assessment where indicated, hearing and vision review, medication review — polypharmacy is a real problem — and functional assessment: strength, balance and the ability to move independently.
How to prepare for the appointment
Bring three things: your first-degree family history written down, the complete list of what you take (including supplements, which interact more than people think) and two or three specific questions. If you've had blood work before, bring the previous results: the trend of a value across years is far more informative than an isolated figure.
When not to wait for the check-up
Some signs aren't managed by calendar: unexplained weight loss, unexplained bleeding, a new lump, chest pain on exertion, breathlessness you didn't have before, a mole that changes, persistent fever or any abrupt, marked change. That isn't a matter for the annual review: it's a reason to be seen now.
What to do with an "abnormal" value
It almost never means what it seems. A value slightly outside range in someone without symptoms is usually repeated before acting, because there's biological and laboratory variability. Reference ranges are constructed such that a percentage of healthy people fall outside by definition. Interpretation depends on the full context, and that context belongs to your doctor, not to a search engine.
A final thought
A good check-up isn't the one that measures the most, but the one that measures what can change a decision. For most healthy people that fits into very little: blood pressure, basic blood work with ferritin, the cancer screenings appropriate for your age and a dental review. Beyond that, each additional test should answer a specific question. Arrive with your family history, your previous results and your questions written down, and let it be a conversation rather than a formality.