Don't Wait for Your Labs to Turn Red: What Blood Tests Should You Get at Your Annual Physical?

You go to your yearly physical. Your doctor orders a handful of labs — a blood count, a cholesterol panel, maybe a blood sugar check. Everything comes back "normal." You feel fine. You go home assuming you're healthy.

Here's the problem: feeling fine and being healthy are not the same thing. The diseases that eventually take away your strength and independence — heart disease, kidney disease, colon cancer, blood cancers, thyroid disease — almost all start silently. By the time they cause symptoms, you've lost years of opportunity to intervene.

I'm an internal medicine and obesity medicine physician, and I built my practice around one idea: don't wait for your labs to turn red. This article walks through exactly how I think about annual screening labs — which tests everyone needs, which ones depend on your story, and the cardiovascular tests most physicals skip entirely.

Why "normal" labs can still miss disease

A standard physical usually includes four or five labs. That's a starting point, not a strategy. Here's what can be happening in your body while your basic panel looks fine:

A polyp or early colon cancer is causing a slow bleed, and you're becoming anemic month by month — but nobody is looking at the trend in your blood counts.

Your kidney function is quietly declining. Caught at stage 3, the management is completely different than at stage 4 — but only if someone is actually checking.

You have Hashimoto's thyroiditis, an autoimmune thyroid condition that's remarkably common in younger women, and it's starting years before you feel tired or notice the hair loss.

Your blood pressure is creeping up because of hyperaldosteronism — a treatable hormonal cause of hypertension and heart failure that most physicians never look for.

Your standard cholesterol panel looks fine, but you inherited high Lp(a) — a genetic cholesterol particle that significantly raises heart attack and stroke risk and is almost never tested.

These aren't rare conditions. They're the conditions I see every month. The common thread: zero symptoms or symptoms that arise gradually and often missed, and a standard physical that wasn't asking the right questions.

So here's the framework I actually use. Every lab I order answers a specific disease question, organized into three tiers.

Tier 1: The core labs — everyone, every year

CBC (complete blood count). Most people think of this as routine. It isn't. A CBC is how I screen for slow gastrointestinal bleeding from a stomach ulcer or colon cancer, anemia from malabsorption conditions like celiac disease or from heavy menstrual bleeding, and blood-count disorders — including thrombocytosis, a very high platelet count that raises risk for blood clots and can be an early sign of blood cancer like leukemia starting silently.

BMP (basic metabolic panel). Kidney function and electrolytes. This is how early kidney disease gets caught before you feel it, how electrolyte problems show up, and where the first clues to hyperaldosteronism appear. It also drives nearly every medication decision I make — I can't prescribe safely without knowing your kidney function.

Lipid panel. Your baseline cardiovascular picture: cholesterol and triglycerides, the raw material of arterial plaque. The lipid panel tells me whether we need to go deeper with the Tier 3 tests below.

A1c. Your average blood sugar over the past three months. This catches prediabetes and diabetes years before symptoms — and intervening at the prediabetes stage is one of the highest-value moves in all of preventive medicine.

Liver function tests (when risk factors are present). If you have obesity, drink alcohol regularly, or have had abnormal labs before, I screen for MASLD — fatty liver disease related to metabolic health — and early cirrhosis. Liver damage is often completely silent until it's advanced.

Tier 2: Targeted tests — when your story calls for it

These labs I add when your symptoms, history, or risk factors make them worth ordering. The skill isn't ordering every test on every patient — it's knowing when a test will actually change management.

TSH (thyroid). For younger women, because Hashimoto's thyroid disease frequently begins without symptoms, and for anyone with fatigue, hair loss, weakness, or headaches. An untreated thyroid problem can masquerade as "just aging" or "just stress" for years. It's treatable.

Ferritin (iron stores). For fatigue, hair loss, headaches, or heavy menstrual bleeding. A low ferritin tells me you're either losing blood somewhere or not absorbing iron and on the other hand a high ferritin could be a sign of disorder metabolizing iron, inflammatory disease or liver disease — and then the real work begins: finding the source.

B12. For numbness, tingling, fatigue, hair loss, or headaches. B12 deficiency causes nerve damage that's reversible when caught early and can become permanent when missed.

Vitamin D. I check this in every obesity medicine evaluation and when there is risk for osteopenia and osteoporosis (bone loss)— vitamin D is fat-soluble and almost always runs low with elevated body fat. My target range is 40–80 ng/mL, which supports long-term bone strength, muscle function, and immune health.

Urine protein. For patients with diabetes, high blood pressure or kidney disease. Protein leaking into the urine is an early warning sign of kidney damage — and catching it early means we can slow or prevent progression.

PSA (prostate-specific antigen). For men in the screening age range — typically starting around 50, earlier with a family history of prostate cancer or other risk factors. PSA is the clearest example of why screening is a judgment call, not a checkbox. The blood draw is simple; the skill is in interpreting it — when to start, how often to repeat, and what a borderline result actually means. Done thoughtfully, PSA catches prostate cancer before symptoms. Done carelessly, it leads to unnecessary biopsies and anxiety. That's a decision we make together, in an unrushed conversation.

Cystatin C. If you take creatine — which I often recommend for muscle preservation — or you simply carry more muscle than average, your standard kidney number can read lower than your actual kidney function. The usual estimate (eGFR) is calculated from creatinine, a breakdown product of both muscle and creatine itself. More muscle and creatine supplementation nudge creatinine up, which can pull that estimate down — modestly on average, but enough to matter for interpretation in some people. Cystatin C is a different marker that's less influenced by muscle mass, and the most accurate approach combines it with creatinine rather than relying on either alone. This matters for a practical reason: I don't raise anyone's protein target without checking kidney function first, and I don't want an artificially low number holding you back when your kidneys are actually fine. (Cystatin C has its own confounders — higher body fat, inflammation, thyroid problems, and high-dose steroids can all shift it — so I use it to refine the picture, not as a standalone replacement.)

Tier 3: The cardiovascular tests most physicals skip

This is where good screening becomes great screening. These two tests change my treatment decisions more than almost anything else on this list — and they're almost never part of a standard physical.

Lp(a) (lipoprotein(a)). A cholesterol particle you inherit from your parents. It's genetic, it doesn't change over your lifetime, and you only need it tested once in your life. If your Lp(a) is high, it changes your entire prevention strategy: you may need cholesterol-lowering therapy earlier and more aggressively than standard guidelines suggest — even if the rest of your lipid panel looks fine. You won't know unless you test it.

ApoB (apolipoprotein B). The protein that carries every plaque-building cholesterol particle in your bloodstream — LDL, VLDL, and Lp(a) carry one ApoB molecule each. That means ApoB directly counts the number of atherogenic particles, not just the amount of cholesterol they carry.

Here's why that matters. Your LDL can look "at goal" while your ApoB is still elevated — meaning more plaque-building particles are circulating than the standard number suggests. This discordance is the hidden culprit behind heart attacks and strokes in people with "normal" cholesterol. And when ApoB stays high despite a statin, it usually means we need more than a statin — adding ezetimibe, bempedoic acid, or a PCSK9 inhibitor to actually lower the particle burden. One practical bonus: ApoB doesn't require fasting.

The deeper reason I order these tests: we fail our patients when we manage only 10-year risk and wait for plaques to advance. A 45-year-old has 30–40 years of cardiovascular life ahead — that's the time horizon that matters.

The point isn't perfect numbers. It's independence.

I spent years managing complex patients in their 60s, 70s, 80s, and 90s. That experience taught me something that shapes every screening decision I make now: the most expensive thing in medicine isn't a hospitalization. It's losing the ability to walk to the bathroom independently.

Every lab on this list is built around one question: will catching this disease early help you stay strong, sharp, and independent at 80? Early kidney disease — yes, because managing it now prevents dialysis and frailty later. Hashimoto's — yes, because treating it gives you the energy to stay active and strong. High ApoB — yes, because preventing a heart attack means you're alive and functional for the decades that matter.

Staying strong, sharp, and independent at 80 isn't luck. It's a plan that starts in your 40s.

What to do with this

Bring this framework to your next physical. Ask which of these labs you're getting and which apply to your situation. If your current doctor isn't engaging with these questions, that's information too.

Want the quick-reference version? I've put this entire framework into a free one-page checklist — every lab, when I order it, and what it rules out. [Download the Annual Lab Checklist here.]

And if you want a physician who screens this way — strategically, unrushed, focused on your independence — that's what Present Future Health is built for. I see patients via telemedicine across Wisconsin and soon Massachusetts. The initial comprehensive consultation is $350 for a full 60 minutes, and pricing is public because you should know what every dollar is buying. Not sure yet? Book a free discovery call and we'll talk through whether this approach fits your situation.

This article is educational information, not personalized medical advice. Which labs are right for you depends on your symptoms, history, and clinical context — that's a decision made with your physician. For emergencies, contact local emergency services.