Routine tests: how a doctor decides what to order — by age, sex and cardiovascular risk

"Doctor, I'd like to have some routine tests done." It is probably the sentence I hear most often at the office — and one of the hardest to answer well. Hard not because there is nothing to order, but because there is no such thing as a "routine test". There is a line of reasoning, which combines three variables: the age, the sex and the cardiovascular risk of the person in front of me. And there is a principle the check-up industry prefers not to mention: every test ordered without an indication has a cost, and it rarely shows up on the laboratory bill.

This article explains how that reasoning works in practice — what changes from one age group to the next, what is different for women and men, how cardiovascular risk reorganizes the list — and why ordering less, with judgement, usually protects more than ordering a lot.

"Routine" is not a list. It is a line of reasoning

When someone asks for "routine tests", they are usually mixing up three different things.

• Screening: looking for a disease in someone who has no symptoms — mammography, HPV-DNA testing, fecal occult blood. It only makes sense when the disease has a silent phase in which treatment changes the outcome, the test is reasonably accurate and early treatment brings real benefit, not just an earlier diagnosis.
• Risk stratification: measuring what helps estimate the chance of a future event — blood pressure, cholesterol, blood glucose, kidney function. These tests do not diagnose a disease; they feed a decision: to treat or not, and how intensively.
• Monitoring: following a condition that already exists — potassium and creatinine in someone on blood pressure medication, glycated hemoglobin in someone with diabetes. That is not screening; it is part of the treatment.

The "complete check-up" package bundles all of this with a dozen tests that belong to none of the three categories. And the evidence on that model is uncomfortable: a 2019 Cochrane review, with 11 clinical trials and more than 233,000 adults, found no effect of general health checks on total mortality (risk ratio 1.00), nor on cardiovascular or cancer mortality. What works is not the generic check-up. It is the right test, for the right person, at the right time.

The three variables

Age

Age is the variable that weighs the most, because most screenable diseases have a window of incidence. Screening before the window produces false positives; screening after it produces diagnoses that would not have changed the course of a life.

• From 18 to 34, the list is short: blood pressure at every visit; a lipid panel at least once — the 2026 American guideline recommends it from age 19, repeated every 5 years if normal; blood glucose only with overweight or obesity plus one risk factor; cervical screening from 25; a hepatitis C test at least once in a lifetime from 18, as the Brazilian Ministry of Health protocol began recommending in 2026, and HIV, syphilis and hepatitis B tests for every sexually active person, repeated after each new exposure; vaccines up to date; and a conversation about tobacco, alcohol, sleep and mental health — which prevents more, at this age, than any blood panel.
• From 35 to 49, diabetes screening comes in for everyone, from 35, regardless of risk factors — fasting glucose and glycated hemoglobin, repeated every 3 years if normal (Brazilian Diabetes Society, 2025). It is also the age range in which the cardiovascular risk estimate starts guiding decisions, and in which mammography can be done from 40 to 49, on request, after a conversation about risks and benefits.
• From 50 to 64, the highest-yield cancer screenings are added: mammography every 2 years, a fecal immunochemical test every 2 years for colorectal cancer and — for heavy smokers — low-dose chest CT, discussed case by case. The PSA conversation comes in here. And it is a conversation, not an automatic order.
• From 65 to 74, mammography (to 74) and fecal occult blood (to 75) continue; bone densitometry comes in for women from 65 — earlier if the risk of fracture is increased; and men who have ever smoked are candidates for a single abdominal aortic ultrasound between 65 and 75.
• From 75 on, most screenings lose their benefit, because the time until the disease would cause harm becomes longer than the life expectancy it would threaten. The decision becomes individual: functional status, other diseases, preferences. The exception is chest CT, which continues to age 80 for those who meet the criteria. What does not stop is the monitoring of what already exists.

Sex

Sex defines the list of cancer screenings and changes how cardiovascular risk is read. One necessary precision: cervical screening applies to anyone who has a cervix — women, trans men and nonbinary people — and is no longer indicated after a total hysterectomy for benign disease, with no history of a high-grade lesion.

• Women: cervix (HPV-DNA every 5 years, from 25 to 64), breast (mammography every 2 years, from 50 to 74) and osteoporosis (densitometry from 65, or earlier with risk factors). The calculated cardiovascular risk tends to be lower than that of a man of the same age with the same test results — but it rises after menopause, and conditions such as preeclampsia, gestational diabetes and premature menopause are risk enhancers that do not enter the equations and need to be asked about.
• Men: abdominal aorta (one ultrasound between 65 and 75, for those who have ever smoked) and the decision about PSA. For osteoporosis, the evidence on screening men is insufficient; the assessment is guided by risk factors.

Cardiovascular risk

This is the variable that reorganizes the list the most — and the least understood. Cardiovascular risk is not "having high cholesterol". It is the estimated probability of a heart attack or stroke in the next 10 years — and, for younger adults, in the next 30 as well —, calculated from age, sex, blood pressure, total and HDL cholesterol, kidney function, diabetes, smoking and current medications. Since 2025, the Brazilian Dyslipidemia Guideline uses the American Heart Association's PREVENT equations for this — the same ones used by the 2026 American guideline and by the calculator on this site's Scientific Profile page.

The result is a risk category — low, intermediate, high, with subdivisions that differ a little between the Brazilian and the American guidelines —, and it is the category, not cholesterol in isolation, that decides what comes next. With three exceptions that bypass the score: LDL of 190 mg/dL or more and, from 40 to 75, diabetes, chronic kidney disease or HIV — in those situations a statin is indicated whatever the category. And one test that applies to every adult, in any category: lipoprotein(a), measured once in a lifetime, because it is genetic, does not change over time and raises the calculated risk.

• Low risk: a lipid panel every 5 years, blood pressure at every visit, glucose according to age. No imaging. A routine electrocardiogram is recommended against in this group (USPSTF, 2018): it does not change management and opens the door to invasive investigations.
• Borderline or intermediate risk: this is where additional tests have a role — not to "see how the heart is doing", but to decide whether starting a statin is worthwhile. The coronary calcium score, which can reclassify risk up or down, is the test with the best evidence in this group — and this is where an elevated lipoprotein(a) weighs the most. It is also the group in which family history, chronic inflammatory diseases and pregnancy-related conditions enter the decision.
• High risk: the conversation stops being about screening and becomes about treatment. A statin, an LDL target, blood pressure and glucose control — and the tests that monitor those targets: a lipid panel after adjustments, kidney function, glycated hemoglobin.
• Established atherosclerotic disease (heart attack, stroke, angioplasty, documented plaque): there is no screening to do. There is intensive treatment and follow-up.

Notice what appears in no category for people without symptoms: exercise stress testing, echocardiography, carotid ultrasound, CT angiography, "hormone panels". Each has a precise indication — and none of them is "routine".

What an unnecessary test costs

A test that should not have been ordered is rarely just useless. It usually produces one of four problems.

False positive. Every test has a rate of abnormal results in healthy people. When the disease is rare in the population being tested — the case of a young, asymptomatic, low-risk adult —, most abnormal results will be false. Each one generates a second test, an extra visit, weeks of anxiety.

Incidental finding. It is the most predictable consequence of "routine" imaging. A 2018 review in the BMJ, pooling 240 studies, found incidental findings in more than a third of chest CT scans and cardiac MRIs, and in about 22% of brain and spine MRIs. Most are benign — fewer than 5% of incidental findings in the brain or the adrenal gland are malignant —, but each one needs to be clarified, and clarifying has a cost.

Cascade. It is the name the literature gives to the sequence of tests, visits and procedures set off by a finding that did not need to be found. In a national survey of American internists published in 2019, 99% reported having experienced cascades of this kind; 68% saw psychological harm to patients, 16% physical harm and 58% financial burden. A third admitted that the test that started the cascade was probably not indicated.

Overdiagnosis. It is the hardest problem to see, because it looks like success: the test finds a real disease that would never have caused symptoms or death. The person is treated — sometimes operated on — for something that did not need treatment. The most studied example is South Korea, where offering thyroid ultrasound as screening multiplied the incidence of thyroid cancer 15-fold between 1993 and 2011, with no change in mortality from the disease. Screening for thyroid cancer in people without symptoms is now formally recommended against.

PSA illustrates the same dilemma with numbers: among men aged 55 to 69, screening prevents about 1.3 deaths from prostate cancer per 1,000 men screened over 13 years. In exchange, it produces false positives, biopsies and treatments whose sequelae are frequent — about 1 in 5 men who undergo prostatectomy are left with persistent urinary incontinence, and 2 in 3 with erectile dysfunction. That is why the Brazilian Ministry of Health does not recommend population screening, and the guidelines that allow it require the decision to be individual and informed.

What usually should not be on the list

Some tests appear in almost every check-up package and in almost no guideline:

• Electrocardiogram, exercise stress test and echocardiogram in adults without symptoms and at low risk.
• Vitamin D in adults without risk factors: the evidence is insufficient for screening, and the result rarely changes management.
• TSH in adults without symptoms: the same conclusion.
• Thyroid ultrasound, "total" abdominal ultrasound and whole-body CT scans without a complaint.
• Tumor markers — CEA, CA-125, CA 19-9, alpha-fetoprotein — in people without symptoms: they do not screen for cancer; they generate cascades.
• "Hormone panels" — testosterone, cortisol, insulin — without a clinical hypothesis.

None of these tests is bad. All have indications in specific situations. The mistake is ordering them out of habit.

How this works at the visit

In practice, deciding what to order takes more time talking than typing. The script I use:

• Age and sex set the baseline: which screenings are within their window.
• The history adds or removes: previous diseases, family history (colorectal or breast cancer in a first-degree relative brings the start forward and changes the method), smoking (which defines chest CT and the aortic ultrasound), pregnancies, medications.
• Blood pressure, a lipid panel, creatinine, glucose, smoking and current medications feed the risk calculator; weight and waist circumference enter the clinical assessment — and the category decides whether the next step is "repeat in 5 years", "let's discuss a statin" or "let's treat".
• What already exists is monitored with the tests for that condition, at the interval for that condition — not "routinely".
• What is left — the dozen tests in the package — is discussed explicitly: why I will not order them, and what I would order if a symptom appeared.

The result is usually a shorter list than the patient expected — and a longer plan: when to repeat each item, what to watch for, when to come back.

For the patient

If you are thinking about "having some tests done", three questions help the conversation with your doctor:

• Which tests are indicated for my age and my sex — and at what interval?
• What is my estimated cardiovascular risk, and what does that number change in what we will order?
• For each extra test I would like to have: what will we do if it comes back abnormal? If the answer is "nothing" or "more tests to confirm it was nothing", the test probably does not need to be done.

A good test is one that changes a decision. The rest is noise — expensive, anxiety-inducing and, sometimes, dangerous.