4 Scenarios When Detailed Testing Makes Sense

medical testingWe have unparalleled abilities to peer inside our bodies and take detailed snapshots of physiological processes and the state of our health. We can measure the hormones in our blood, the cholesterol in our veins, the nutrient deficiencies we may have. We can go deep. But it doesn’t always make sense to take that deeper, more detailed look at the numbers. It gets expensive, for one. It gets intrusive. Our doctors may be resistant. And it can provide a bit too much of a close look when a broader view might suffice.

When do more detailed tests make sense, though? What kind of scenarios call for a second, deeper look at our numbers?

“You’re fit as a fiddle, you’ve clearly lost a ton of weight, but your cholesterol’s a little high. We better get that handled.”

This is the classic scenario seen time and time again in the Primal and keto community.

Killing it in the gym.

Leaner than you’ve been since your teens.

Off all meds.

Pre-diabetes trend reversed.

More energy than ever.

Just feeling great overall.

But your LDL’s a little high. Or a lot. And the doc’s recommending that, while all these improvements are great, we do something about the cholesterol. Before you “take action,” let’s confirm you actually have elevated LDL.

If your triglycerides are under 100, and your LDL is calculated using the Friedewald equation, it will significantly overestimate your LDL numbers.

Say they directly measure your LDL-C and it’s still high. What then?

Then you should measure your LDL particle number. Elevated LDL particle number is what many “progressive” lipid experts say is the true cause of atherosclerosis—by increasing the number of particles in circulation, you increase the number that will penetrate the arterial wall and trigger an atherosclerotic lesion. ApoB is another measurement to take; it’s roughly analogous to LDL particle number, as each LDL particle contains an ApoB protein.

If your LDL-P or ApoB is still high and in the “danger zone,” what do you do? Do you go back on everything that worked for all the other health barometers?

I honestly don’t know. The question of elevated LDL particle number as an independently sufficient cause of heart disease is far from settled (and I suspect there’s more to it than that). But at least with more detailed testing you’re better equipped to have that conversation.

“Your TSH is normal. I don’t know why you’re feeling rundown all the time, but it’s not the thyroid.”

For most people, TSH is the best barometer of thyroid function. After all, if thyroid-stimulating hormone is normal, then your body feels like it’s getting plenty of thyroid hormone. There’s no “emergency.” If TSH is elevated, then your body doesn’t feel like it’s getting enough thyroid hormone. That’s how it usually works. In theory.

But what if your TSH is normal, not elevated, but you’re still feeling all the symptoms of low thyroid activity? What if you can’t get up in the morning, you’ve been gaining weight, you’re freezing all the time, and you generally feel very low energy?

What you don’t want to do is take the “expert” opinion at face value. No, that person who isn’t you doesn’t have unique and superior insight into how you’re feeling. No, the number doesn’t negate your subjective experience of symptoms. If you’re feeling bad, you need to do further testing.

Okay, so what should you test?

You’ll want to start with T4. T4 is “inactive” thyroid hormone that gets converted to “active” thyroid hormone (called T3) throughout the body. The thyroid gland makes mostly T4 and some T3 directly. In most people, a normal T4 means normal thyroid function.

Can you have normal TSH, normal T4, and still have underactive thyroid function? Yes.

If your peripheral tissues that normally convert T4 to active T3 aren’t doing it, you will effectively have poor thyroid function. The thyroid hormone is there, the tests look good; it’s just not doing its job.

Okay, so then you test T3 in addition to T4 and TSH. All good, right?

It’s better because it gives you an idea of active thyroid hormone in circulation, but it might not be enough. Even if your T4 and T3 levels are good, if they remain bound to the protein carrier that delivers them around the body, they can’t perform the jobs we all expect our thyroid hormones to perform.

You may need to test Free T3 and Free T4. Those are “unbound” thyroid hormones. They are the truly active ones.

Another test to consider is the thyroid antibody test. This helps determine whether your thyroid dysfunction is caused by an autoimmune response, and it can help you map your response.

“You’re pregnant.”

You hear these words and time stops. It’s really happening. You’re actually building an entire human being from start to finish—inside your body.

At least, I imagine that’s probably what it feels like. I wouldn’t know from personal experience. Being a father (and now grandfather) is powerful enough.

But it’s a big deal. And it’s a lot of responsibility, especially as a health-conscious individual who reads nutrition blogs and forks out cash for grass-fed meat and avocado oil mayo will understand. You know how important each day of your pregnancy is. You know how the food you eat and the nutrients you are and are not deficient in can affect the trajectory of your baby’s development.

Vitamin D is one of the more important things to test as a pregnant lady. Ideally you’d do this well ahead of time, so you go into it with good vitamin D levels, but testing early in the pregnancy is also a good move. Emerging evidence suggests that vitamin D deficiencies during pregnancy can increase the risk of ADHD in the child.

It isn’t standard. You’ll have to request it. But it might be worth the trouble if you think you’re deficient, especially since it’s an easy fix.

“Your testosterone is normal. I don’t know why you think you might need HRT.”

You can have normal testosterone and still have symptoms of low-T.

Lack of energy. Reduced libido or absent morning wood. Middling results in the gym. Decreased motivation and drive. These aren’t “serious medical conditions,” and many doctors will disregard them if your numbers turn out normal. That doesn’t help you, though, does it? These symptoms are no small matter. They seriously impact your quality of life, productivity, relationships (with yourself and with others), and they presage warning signs for your health down the road (muscle, insulin sensitivity, etc).

If your testosterone looks normal but you still have symptoms, what you need is a full panel that at the very least checks:

  • Free testosterone: active testosterone. Just like thyroid hormone, you can have normal testosterone levels but if it’s all bound up and inaccessible, you may have symptoms of low testosterone. Free T gives you a good picture.
  • Sex hormone binding globulin: high levels can bind to your testosterone, rendering less of it “free” and bioavailable.

Once you have good information, you can figure out a plan of attack to address your testosterone situation.

That’s it for today, everyone. Can you think of any other situations that call for detailed testing? Let me know down below!


Ahmadi SA, Boroumand MA, Gohari-moghaddam K, Tajik P, Dibaj SM. The impact of low serum triglyceride on LDL-cholesterol estimation. Arch Iran Med. 2008;11(3):318-21.

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending more than three decades educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates flavorful and delicious kitchen staples crafted with premium ingredients like avocado oil. With over 70 condiments, sauces, oils, and dressings in their lineup, Primal Kitchen makes it easy to prep mouthwatering meals that fit into your lifestyle.

If you'd like to add an avatar to all of your comments click here!