Health tests you should not ignore after 30: From blood sugar to cancer screening

Imagine being able to detect a disease before it causes symptoms or being able to identify risk factors years before a heart attack or stroke occurs. Modern medicine cannot predict the future with certainty, but a few carefully chosen tests can help us identify people at higher risk and, importantly, act early.

Heart attacks, stroke and cancer account for a large proportion of deaths and disability worldwide. In India, cardiovascular disease is a particularly important cause of premature illness and death, making early identification and control of risk factors crucial. 

But there is an important caveat: more testing is not necessarily better testing. A long list of blood tests, whole-body scans and 'tumour markers' can produce false alarms and unnecessary anxiety. The best strategy is evidence-based screening tailored to age, sex and individual risk factors.

For everyone: Know your cardiovascular numbers

Blood pressure

High blood pressure is often called a 'silent killer' because it may cause no symptoms while gradually damaging the heart, brain and kidneys. Every adult should know their blood pressure. A practical approach is to check it periodically from adulthood and at least annually after age 40 or earlier in those with obesity, diabetes, kidney disease or a family history of hypertension. An elevated reading should be confirmed with repeat measurements, preferably including home or ambulatory monitoring.

Blood sugar

India faces a high burden of diabetes, which substantially increases the risk of heart attack and stroke. The ICMR recommends screening all adults above 30 years of age, and earlier testing in those with risk factors such as obesity, a family history of diabetes, high blood pressure or a sedentary lifestyle. Fasting glucose and HbA1c are commonly used tests. 

Cholesterol and beyond

A lipid profile remains the foundation for assessing cardiovascular risk. Depending on age and risk factors, your doctor may also recommend ApoB, which reflects the number of cholesterol-containing particles capable of entering artery walls.

Another useful test is lipoprotein(a), or Lp(a). This is largely inherited and can increase cardiovascular risk even in someone with an otherwise healthy lifestyle. Contemporary guidelines recommend measuring Lp(a) at least once during adulthood. 

For selected middle-aged adults in whom the need for preventive treatment is uncertain, a coronary artery calcium (CAC) scan can reveal silent calcified plaque in the coronary arteries. It is not a routine test for everyone but can help personalise prevention in the right person.

Cancer screening

Unlike cardiovascular risk testing, cancer screening is specific to individual cancers. Unfortunately, there is no single blood test or scan that can reliably screen everyone for all cancers.

Women

Breast cancer: 

Mammography is an effective screening tool for many women. Major international guidelines recommend screening mammography from age 40 to 74, although the interval and starting age may vary between guidelines and should be individualized based on family history and other risk factors. Women with a strong family history or genetic predisposition may need earlier and more intensive screening. 

Cervical cancer: 

This is one of the great success stories of prevention because screening can detect precancerous changes before cancer develops. HPV testing and Pap smears are the principal tools. Women should discuss the appropriate method and interval with their gynaecologist based on age and previous screening history. Importantly, HPV vaccination complements, but does not eliminate the need for appropriate screening. 

Men

Should everyone have a PSA test?

The PSA blood test can help detect prostate cancer early, but it is not a simple 'yes or no' screening test. It can also lead to unnecessary biopsies and treatment of slow-growing cancers that might never have caused harm.

For men around 50 years and above, particularly those with a reasonable life expectancy, an informed discussion with a doctor about the benefits and limitations of PSA testing is sensible. Men with a strong family history may need to begin this discussion earlier. 

For both men and women: don't forget the colon

Colorectal cancer screening can detect cancer early and colonoscopy can even remove precancerous polyps before they become cancerous. Several guidelines recommend beginning screening at 45 years of age for average-risk adults. Options include a stool-based test such as FIT or colonoscopy, with the choice depending on availability and individual preference. People with a family history of colorectal cancer or certain bowel diseases may require earlier screening. 

Smokers deserve greater attention

For people aged 50–80 years with a significant smoking history, annual low-dose CT scanning can reduce deaths from lung cancer in carefully selected high-risk individuals. It is not recommended for everyone and it should never distract from the single most effective preventive intervention: quitting smoking. 

What tests should you avoid?

Be cautious about expensive 'executive health packages' that include numerous tumour markers, whole-body CT or MRI scans without a clear indication. These tests can uncover harmless abnormalities, triggering a cascade of further investigations.

Screening is not about finding the maximum number of abnormalities. It is about finding the conditions where early detection has been proven to improve outcomes.

Starting in adulthood, know your blood pressure, blood sugar and cholesterol profile, and discuss additional tests such as Lp(a), ApoB or CAC based on your individual risk. As you grow older, add age- and sex-appropriate cancer screening.

The opinions expressed in this article are those of the author and do not purport to reflect the opinions or views of THE WEEK.