Ever wonder if your annual check-up is catching all the right things? What if you're missing a crucial blood test that could have easily prevented a serious health issue like a heart attack?
In this blog post, I'll reveal 5 lifesaving blood tests that everyone should get, plus another 4 that certain groups of people should also consider.
And if one of these tests reveals something concerning, don't worry - I'll guide you through the next steps to protect your health. Plus, I'll explore whether specific blood tests can help with early cancer detection and what you need to know about them.
Table of Contents
- Lipoprotein(a) (Lp(a)) Test: The Overlooked Silent Risk
- Lipid or Cholesterol Panel: Understanding the Numbers
- The Evidence Behind Lowering LDL Cholesterol and ApoB
- Statins: Addressing the Concerns
- HbA1c Test: Monitoring Blood Sugar Levels
- Kidney Function Tests: The Body's Filters
- Full Blood Count: The Early Warning System
- Why Not Test for Everything? The Role of Pretest Probability
- Four Additional Blood Tests Certain Groups Should Consider
- Conclusion: Focus on What Matters
- References
Lipoprotein(a) (Lp(a)) Test: The Overlooked Silent Risk
Let's dive in, starting with a test that's often overlooked by family doctors, yet is recommended by the European Atherosclerosis Society. It's called Lipoprotein(a), or Lp(a).
Lipoproteins are like the trucks that carry cholesterol around our bodies. And just like how some trucks carry dangerous cargo, high levels of Lp(a) are a major risk factor for heart disease, aortic valve problems, and even death. This risk doesn't discriminate - it affects everyone, regardless of gender or ethnicity.
According to the American College of Cardiology, "Observational and genetic evidence strongly support the conclusion that high Lp(a) concentration is causal for ASCVD, aortic valve stenosis, and cardiovascular and all-cause mortality in men and women and across ethnic groups".
What's tricky about Lp(a) is that it's mostly determined by our genes. Unlike other lipoproteins, diet and exercise won't lower our Lp(a) levels. The same source emphasizes, "Lifestyle interventions have minimal impact on Lp(a)".
That's why the European Atherosclerosis Society suggests everyone gets tested at least once in their adult life. The consensus is clear: "This panel recommends testing Lp(a) concentration at least once in adults".
If our Lp(a) levels are high, it's a red flag that we need to double down on controlling other heart attack risks. This means paying extra attention to our diet, exercise, blood pressure, and avoiding smoking and alcohol. Managing stress is crucial too - think of it as reinforcing all the walls if one is already showing cracks.
So, what's a good Lp(a) result? The European Atherosclerosis Society suggests that ideally, we'd have a level below 30mg/dL or less than 75nmol/L. The good news is that 75% of us will be below that number. But if we're above the ideal range, it means we need to be a bit more aggressive with treating the other heart attack risk factors.
Lipid or Cholesterol Panel: Understanding the Numbers
Next up is the second of our 5 lifesaving tests: a lipid or cholesterol panel. The key here is the interpretation of the results.
A standard lipid panel includes total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides. There's a lot of confusion online about blood cholesterol levels, so let's clear that up.
First of all, cholesterol is essential for life. We can't live without it. It helps to make our cell membranes, hormones like testosterone, and bile for digesting fats. No cholesterol means no life. The good news is that we've known for decades that all cells in the body can produce their own cholesterol. As a study explains, cholesterol is "also synthesized by every cell in the body".
Primarily, cholesterol is transported in vehicles called lipoproteins. That's what we're measuring in a lipid panel. Since we're only measuring the cholesterol levels in the blood, we're only measuring a tiny fraction of the body's total cholesterol content.
But when there's too much LDL cholesterol in our blood, it can get dumped into our artery walls, like trash piling up on a highway, eventually leading to blockages that cause heart attacks and strokes.
Some people suggest paying for additional tests like oxidized LDL or small dense LDL, claiming these are the real culprits. But that's missing the point. What we're really looking at are the vehicles - lipoproteins - that carry cholesterol. The ones that carry an ApoB tag are the troublemakers, including all those small, dense LDL particles.
These particles cross from the bloodstream into the blood vessels, and if there's a high enough concentration, they become trapped in the artery wall.
So, if you're looking for a more precise test, consider an ApoB test. But be aware, it generally doubles the cost, which is why most guidelines stick to measuring LDL cholesterol.
The Evidence Behind Lowering LDL Cholesterol and ApoB
So, what evidence do we have that lowering LDL cholesterol and ApoB reduces heart attacks? Meta-analyses like this one, which combine data from genetic studies and randomized controlled trials over 20 million person-years of follow-up, conclusively prove that LDL causes heart disease. According to the study, "Consistent evidence from numerous and multiple different types of clinical and genetic studies unequivocally establishes that LDL causes ASCVD."
Some "experts" on YouTube who unfortunately don't follow the clinical guidelines will argue that ApoB and LDL cholesterol aren't the issue. They'll say it's insulin resistance, obesity, smoking, a sedentary lifestyle, and high blood pressure that cause heart disease. And if those factors are optimized, then we don't need to worry about blood cholesterol.
Well, the PESA study answers those "experts." This study found that even in people with perfect risk factors - no obesity, no smoking, no high blood pressure - blockages still form as LDL cholesterol levels rise. The study highlights, "Even in individuals with "optimal" values for all CVRFs, there was a significant correlation between low-density lipoprotein cholesterol (LDL-C) concentration and the presence of atherosclerosis."
It was only when LDL-c was below 60mg/dL that no blockages in the blood vessels were seen.
Another study published in the Journal of the American College of Cardiology this year (2024) shows that for people without any other heart risk factors, as LDL cholesterol and ApoB increase, so too does the extent of blockages in our blood vessels.
There's even a suggestion now in the literature that the optimal LDL-c level appears to be the level present at birth, which is around 20-40mg/dL.
Some people worry that lowering cholesterol too much could be harmful. But as explained earlier, all cells in our body can produce their own cholesterol, and the blood levels we measure only represent a tiny fraction of the body's total cholesterol content. Studies show that even when LDL is below 40mg/dL, there are no concerning side effects.
And just to clarify, the brain makes its own cholesterol and doesn't rely on what's in the blood.
So, what ranges are we looking for? That will depend on our risk factors, but as a broad, oversimplification, if we've already had a heart attack or stroke, the goal is to bring LDL down as low as possible via a combination of diet, exercise, and cholesterol-lowering therapies such as statins, ezetimibe, and PCSK9 inhibitors.
Statins: Addressing the Concerns
Statins often get a bad rap for side effects, so let's explore these briefly. Statins cause muscle aches in about 1-2% of people, but the risk is even lower for low-dose statin therapies, which is what I prescribe for my patients. We get most of the benefits from low-dose statins.
Statins are not associated with cognitive impairment, nor do they affect testosterone levels.
If there are no heart disease risk factors like high blood pressure, diabetes, family history, smoking, etc., then a reasonable target is to get your LDL cholesterol below 70. Personally, I'm targeting a lower level, below 60, but that's my personal choice because I want to do everything I can to prevent a heart attack or stroke when I'm 70 or 80. I take rosuvastatin 5mg to help bring my levels down.
HbA1c Test: Monitoring Blood Sugar Levels
Moving on to the third lifesaving test - HbA1c. The HbA1c test reveals our average blood sugar levels over the past 2-3 months. It's like checking the weather pattern instead of just today's temperature.
You may see online recommendations to get insulin blood tests or for non-diabetic patients to pay for continuous glucose monitors. Your money, your call, but as a screening test for what primary care physicians like myself are interested in for preventative care, those tests don't change clinical practice.
Instead, if we discover that a patient is pre-diabetic from the HbA1c level, we need to really step up our game. We need a diet that's rich in non-starchy vegetables, legumes, nuts, whole fruits, and whole grains. High-protein foods like fish and chicken also help. We want to avoid sugary, processed foods, fruit drinks, and "junk food."
Studies even suggest that prescribing metformin to pre-diabetics can reduce the risk of developing full-blown diabetes. Psyllium husk and GLP-1 medications, like Ozempic, are other options to consider.
Kidney Function Tests: The Body's Filters
The fourth test is kidney function, specifically sodium (Na), potassium (K), and creatinine. Your kidneys are the body's filters, and these tests are like the dashboard lights in a car. They give us an early warning if something's wrong. If a problem is detected, it's essential to follow up with a doctor immediately.
Full Blood Count: The Early Warning System
Finally, the fifth test is a full blood count. A full blood count checks your red blood cells, white blood cells, and platelets. It's a basic test, but it can reveal anemia, infections, or other hidden issues. If anything is off here, it prompts your primary care physicians to jump into action and figure out if there are any underlying issues.
In terms of tests that everyone should get, that's it. For the 5 tests that everyone should get, as long as no issues were revealed when first tested, I encourage my 18-35-year-old patients to have their levels checked every 2-3 years. And my patients over 35 to have their levels checked yearly.
Why Not Test for Everything? The Role of Pretest Probability
But you might be wondering, if money was no object and testing is so important, why not test everyone for everything, all the time?
Here's the thing: No test is perfect. They all have false positives and false negatives. Imagine running a test for a rare condition that affects 1 in 10,000 people, but the test has a false positive rate of 1 in 1,000. For every 10 positive results, 9 would be incorrect. That's not very helpful, is it?
This is why doctors focus on pretest probability. We don't just order tests at random - we use our experience and medical history to narrow down what tests are necessary. This approach helps avoid unnecessary worry and potential harm from unnecessary tests.
Four Additional Blood Tests Certain Groups Should Consider
For certain groups of people, there are additional tests worth considering:
As I mentioned earlier, I'm on a statin, so I get my liver tests done once a year. Other people who need their liver tested include those who drink alcohol, are overweight, or are on other medications. But for otherwise healthy people who aren't on any other medications, the guidelines do not suggest routinely checking liver function because there's no added benefit.
The approach here is very similar to liver function testing. The guidelines suggest testing thyroid function if there's a clinical reason to do so, like symptoms of fatigue, hair thinning, or weight gain. But for healthy people with no symptoms, there's no added benefit, which is why the guidelines do not recommend routine screening. Once again, your money, your health, your decision - so you can, of course, test your thyroid, but it's not part of the clinical guidelines.
People who have a medical condition like inflammatory bowel disease or celiac disease may need testing for specific vitamins and minerals to make sure they're absorbing enough. But for otherwise healthy people who are eating a good diet and taking a low-dose multivitamin & mineral supplement, there's no advantage.
I recently did an in-depth video about Vitamin D testing that you can check out (it's in the next section below).
Men can use PSA tests as a screening tool for prostate cancer, but currently, that's the only screening tool with enough evidence to be recommended by the clinical guidelines.
There's also the Galleri blood test for cancer screening that is being actively researched, but right now, there's not enough evidence to suggest this test will save lives or improve survival times for cancer. Fingers crossed for the future.
Conclusion: Focus on What Matters
Testing for everything might seem like a good idea, but in reality, it can lead to more confusion than clarity. The best approach is to focus on the tests that have been proven to make a difference, based on your individual risk factors and health status. And remember, it's not about limiting your options - it's about making sure the tests you do get are actually helping you stay healthy.
If you want to learn more about the latest guidelines, check out my video on Vitamin D supplements and blood tests:
The Endocrine Society just released an important update that sheds light on why we don't need to test everyone's vitamin D levels.
References
- American College of Cardiology on Lp(a)
- European Atherosclerosis Society on Lp(a)
- Cholesterol Synthesis
- ApoB Lipoproteins and Arterial Retention
- LDL and Heart Disease Meta-Analysis
- PESA Study
- Optimal LDL-C Level at Birth
- LDL-C Levels and Adverse Events Meta-Analysis
- Brain Cholesterol Independence
- European Society of Cardiology Guidelines on Lipid Control
- Statin Muscle Pain Study
- Statins and Cognitive Impairment
- Statins and Testosterone