By Dr. Shiv Kumar Goel, MD · Medically reviewed October 2026
He’d printed the lab result and highlighted the number in yellow before he came in. Call him Marcus, a composite drawn from the men who sit in that chair with the same printout most weeks, not one patient. Total testosterone: 410. In range. His primary care doctor had glanced at it and told him he was fine, maybe try exercising more. He was fifty-two. No interest in sex for the better part of a year. Tired by two in the afternoon most days regardless of how he’d slept. Irritable with his kids in a way that embarrassed him. He didn’t say much of that out loud in the first visit. Men rarely do. What he said was: the number’s normal, so what’s actually wrong with me.
Not nothing. The number he was handed answers a narrower question than he thinks it does.
Total testosterone vs. free testosterone
Total testosterone measures everything in the blood: the hormone that’s free and active, and the hormone that’s bound up to a protein called sex hormone-binding globulin, or SHBG, and functionally unavailable to his tissues. Two men can carry the identical total testosterone number and live in different bodies, because SHBG isn’t fixed. It rises with age. It rises with thyroid changes, with liver conditions, with some medications. Marcus was fifty-two. Age alone pushes SHBG up a little every decade, and his had crept up enough that it was quietly binding more of his testosterone than a thirty-year-old’s would at the identical total number. Extra weight usually pulls SHBG the other way, which is one more reason the total number by itself can mislead in either direction.
This isn’t a fringe read. The Endocrine Society’s own clinical guideline says it directly: “In men whose total T is near the lower limit of normal or who have a condition that alters sex hormone-binding globulin, we recommend obtaining a free T concentration using either equilibrium dialysis or estimating it using an accurate formula” (Bhasin et al., J Clin Endocrinol Metab, 2018). Marcus’s 410 sat closer to the lower end of what most labs print as normal. And he had exactly the kind of profile that alters SHBG. He was the textbook case for the second test that almost never gets ordered.
We ran it. His free testosterone came back low, well below what his total number alone suggested. His body wasn’t lying to him for a year. The first test had just been the wrong instrument for the question he was actually asking, which wasn’t “is testosterone present in my blood.” It was “does my body have enough usable testosterone to run on.”
Marcus’s symptom list, once he stopped leading with the number and told me the rest, was longer than the one line he’d rehearsed. Energy gone by early afternoon most days. No drive for anything that used to interest him, not just sex. Muscle that seemed to be disappearing despite lifting the same as always. Sleep that felt unrefreshing even on the nights he got enough of it. Mood flatter and shorter-tempered than he recognized in himself. That cluster is the common presentation, not an unusual one, and a normal total testosterone doesn’t rule any of it out on its own.
Part of why this gets missed isn’t that anyone did anything wrong. A busy primary care visit runs one panel, checks the box against a reference range printed by the lab, and moves to the next patient. That’s not negligence. It’s a system built for speed, applied to a question that needs a second look instead. And a normal total number is genuinely reassuring in a lot of men. It just isn’t reassuring in every man, and nobody’s chart says which kind he is until someone checks.
What else looks like low T
None of this means every tired, low-drive man needs testosterone therapy. Before that conversation even starts, sleep apnea, depression, thyroid disease, and heavy alcohol use all produce a symptom picture that can look identical to low T, and some of them lower testosterone directly enough that treating the underlying cause fixes both problems at once. A responsible workup rules those out before it reaches for a prescription pad, not after.
Why timing of the blood draw matters
There’s a second piece to this most men never hear either. A single testosterone draw, like a lot of hormone testing, is sensitive to when and how it’s taken. Levels run highest in the morning and decline through the day, so an afternoon draw can understate a genuine deficiency, and a rough night, a recent illness, or even a hard training block can shift a single reading enough to matter. One number, drawn once, at the wrong hour, has sent more than one man home reassured when he shouldn’t have been.
What a proper workup includes
So when a man walks in with symptoms and a “normal” printout, a proper workup starts with a repeat morning draw, fasting, because timing alone can move the number enough to change the read. It measures free testosterone by equilibrium dialysis or a validated calculation rather than total testosterone alone. That distinction matters most in exactly the men whose SHBG is likely to be elevated.
It measures SHBG and LH directly too. Where the problem actually sits, in the testes themselves or in the signal coming from the pituitary, changes what helps. And it looks at thyroid function and metabolic markers in the same draw, since several conditions that alter SHBG produce a low-T picture that isn’t low T at all.
Marcus wasn’t imagining the exhaustion or the flatness or the distance from his own kids that he couldn’t explain. His labs eventually agreed with him. It took a second test to ask the right question, and a physician willing to look past the first number instead of closing the chart on it.
If a testosterone result came back “normal” and nothing about how you feel matches that word, the number isn’t the whole answer. It’s the start of a better question.
Questions patients ask me
Can you have low T symptoms with a normal testosterone level?
Yes. Total testosterone counts hormone that’s bound to SHBG, which your tissues can’t use. If SHBG runs high, free testosterone can be low even when the total looks normal.
What’s the best time for a testosterone blood test?
Early morning, fasting, and repeated on a second day. Levels run highest in the morning, so an afternoon draw can understate a real deficiency.
What should be checked besides total testosterone?
Free testosterone by equilibrium dialysis or a validated calculation, SHBG, LH, thyroid function and metabolic markers. Sleep apnea, depression and heavy alcohol use can look like low T, so they get ruled out too.
Related reading: Why do my perimenopause labs come back normal when I feel awful? and What happens when you stop semaglutide or tirzepatide.
If your number came back normal and you still don’t feel like yourself, you can book a visit here.
About the author. Dr. Shiv Kumar Goel, MD, is an internal medicine physician trained at Mount Sinai and the founder and medical director of Prime Vitality Care in San Antonio. He has practiced medicine for 25 years, served as an assistant professor of internal medicine at Texas Tech University Health Sciences Center, and is certified in functional medicine by the American Academy of Procedural Medicine. His writing appears in KevinMD, Doximity Op-Med, San Antonio Medicine, and the San Antonio Express-News. Read his full bio →
This article is for education and isn’t a substitute for care from your own physician.
