Screening Tests That Are Often Overlooked in Routine Check-Ups

The CDC estimates that more than one in three American adults has prediabetes — and the vast majority are unaware of it. The USPSTF recommends blood glucose screening for adults aged 35 to 70 who are overweight or have obesity, but providers don't always initiate the conversation unless a patient raises it. A simple fasting blood glucose test or HbA1c test (which measures average blood sugar over roughly three months) can identify elevated risk before full diabetes develops. Catching prediabetes early opens the door to lifestyle changes that can reverse or significantly delay progression.

The thyroid gland regulates metabolism, energy, mood, and more — yet thyroid dysfunction often goes undetected for years. Hypothyroidism (an underactive thyroid) is particularly common in women over 60 and can mimic aging or depression. While there is no universal USPSTF recommendation for general population thyroid screening, many clinical guidelines suggest testing in symptomatic individuals or those with risk factors such as a family history of thyroid disease, prior radiation exposure, or autoimmune conditions. A TSH (thyroid-stimulating hormone) blood test is the standard first step. If you've experienced unexplained fatigue, weight changes, or mood shifts, it's worth raising with your provider.

An abdominal aortic aneurysm — a bulge in the main artery running through the abdomen — typically produces no symptoms until it ruptures, at which point it becomes life-threatening. The USPSTF recommends a one-time ultrasound screening for men aged 65 to 75 who have ever smoked (defined as 100 or more cigarettes in a lifetime). Despite this clear recommendation, the test is underutilized. It's painless, non-invasive, and takes only minutes. Men in this age and risk group should confirm with their provider whether they've had this screening.

Hepatitis C is a viral infection that damages the liver over decades, often without noticeable symptoms. The CDC and USPSTF both recommend one-time HCV screening for all adults aged 18 to 79, with more frequent testing for those at ongoing risk. Yet awareness of this recommendation remains low. People born between 1945 and 1965 — the so-called "baby boomer" generation — have significantly higher rates of infection, largely due to medical practices and behaviors common before widespread HCV awareness. A simple blood test can confirm or rule out infection, and effective treatments now exist that can clear the virus in most cases.

Hearing loss and vision decline are among the most common — and most quietly accepted — changes in aging adults. Yet both are strongly linked to broader health outcomes. Untreated hearing loss, for example, has been associated in multiple research reviews with increased cognitive decline risk, social isolation, and depression. Vision problems raise fall risk, particularly in older adults. Neither is routinely tested at a general check-up unless a patient reports trouble. The preventive value of vision and hearing checks is often underestimated — if you haven't had either assessed in several years, it's worth scheduling.

Lung cancer is among the leading causes of cancer death in the United States, yet it's highly survivable when caught early. The USPSTF recommends annual low-dose computed tomography (LDCT) screening for adults aged 50 to 80 who have a significant smoking history (defined as 20 pack-years) and who currently smoke or have quit within the past 15 years. Despite this recommendation, uptake remains far lower than for other cancer screenings. This test is distinct from a standard chest X-ray and requires a specific referral. Eligible individuals who haven't been screened should raise it explicitly with their provider, as it won't typically come up unprompted. For broader context, see when cancer screenings are generally recommended.