Nicolette: 0:01

Welcome to the Health Pulse, your go-to source for quick, actionable insights on health, wellness and diagnostics. Whether you're looking to optimize your well-being or stay informed about the latest in medical testing, we've got you covered. Join us as we break down key health topics in just minutes. Let's dive in.

Rachel: 0:29

Welcome to the Deep Dive. Okay, so we've all been there, right? That feeling after a crazy week or maybe a terrible night's sleep where you just feel completely drained. Oh, absolutely that bone-tired feeling, yeah. But what if that feeling, you know, never really lifts? What if you wake up tired? You stay tired and it feels like you're running on fumes pretty much every day, no matter how much sleep you think you're getting. Well, today we're doing a deep dive into exactly that Understanding chronic fatigue, Not just seeing it as like a bad mood or something, but as a really crucial signal your body might be sending.

Mark: 1:01

That's a great way to put it, a signal.

Rachel: 1:03

So our mission today, looking at current research and clinical stuff, is to unpack some of the most common reasons why people feel so persistently tired, specifically the things that well targeted lab tests can actually reveal. The goal is really to help you go from just guessing, or maybe just enduring it, to actually knowing what might be going on.

Mark: 1:23

Yeah, and it's such an important topic because, honestly, fatigue is so incredibly common. But, it often gets brushed aside. People think, oh, I'm just stressed, or I just need a vacation, or coffee, or more coffee, exactly, but fatigue itself. It's not really a diagnosis, it's more of a downstream effect. There could be dozens of different root causes, these upstream issues and finding the right tests. Well, that's how you figure out which upstream issue is your issue. It really helps you go from, like you said, guessing to knowing.

Rachel: 1:55

Absolutely. And maybe a little pro tip for everyone listening right at the start If this fatigue, this deep tiredness, has been dragging on for longer than, say, three weeks, or if it's really getting in the way of your work or your mood, maybe even, just, you know, getting some exercise, yeah, it's probably time to stop just trying to push through. It's really time to test.

Mark: 2:15

Agreed. Pushing through often just digs the hole deeper.

Rachel: 2:18

So let's jump in. Let's explore how specific lab tests can start to uncover these real culprits behind that exhaustion.

Mark: 2:26

Let's do it.

Rachel: 2:27

Okay. So when we're talking energy, where do we often start looking first in the body? I know one really common and thankfully often treatable cause for fatigue is anemia, specifically iron deficiency anemia.

Mark: 2:40

Yes, definitely a primary suspect.

Rachel: 2:42

We know iron's crucial for hemoglobin right Carrying oxygen everywhere. But what's something people might miss? Even listeners who are pretty health savvy like maybe their standard hemoglobin test looks fine.

Mark: 2:55

That is such a key point. The nuance here is critical. Hemoglobin tells you about the oxygen your blood is carrying right now.

Rachel: 3:02

Okay.

Mark: 3:03

But it doesn't necessarily tell you about your iron reserves. Lots of people I mean lots can have normal hemoglobin levels on a test but feel absolutely wiped out.

Rachel: 3:12

Why is that?

Mark: 3:13

Because their ferritin level, which is the protein that stores iron in your body, is scraping the bottom of the barrel.

Rachel: 3:18

Ah, the storage tank is empty.

Mark: 3:20

Exactly, and standard lab ranges for ferritin can be well incredibly wide. Some Exactly, and standard lab ranges for ferritin can be well incredibly wide. Some labs might call anything over 10 gm normal 10?

Rachel: 3:28

Wow, that seems low. If you're feeling fatigued.

Mark: 3:30

It really is For optimal energy, for good brain function, especially if fatigue is the main complaint. We're often looking for ferritin levels, you know, maybe closer to 70 ngml or even higher in some cases 70.

Rachel: 3:43

Okay, that's a big difference from 10.

Mark: 3:45

Huge difference. A low ferritin means your body is already running on its backup generator, dipping into those reserves, and those reserves can get really depleted long before your hemoglobin actually drops into the anemic range on the standard test.

Rachel: 3:58

That's a super important distinction. Okay, so let's say someone checks the ferritin, optimizes their iron, their oxygen delivery seems okay, but they're still dragging. Where do we look next? The body's main energy regulator, maybe the thyroid?

Mark: 4:11

Yep. The thyroid is absolutely the next major stop on the fatigue investigation tour. It controls metabolism, body temperature, energy levels. It's hugely important.

Rachel: 4:21

We know it's critical, but what's a common maybe red herring here, something that might make someone think their thyroid is fine, even when it's the root cause of their fatigue?

Mark: 4:32

Well, the biggest one, honestly, is relying solely on the TSH test thyroid stimulating hormone.

Rachel: 4:37

Right, that's often the first, sometimes the only one checked.

Mark: 4:40

Exactly, and the problem is TSH isn't actually a thyroid hormone itself, it's a hormone from the pituitary gland telling the thyroid what to do.

Rachel: 4:50

Okay, so it's like the manager, not the worker.

Mark: 4:52

Kind of yeah.

Rachel: 4:53

Yeah.

Mark: 4:53

You can have a TSH level that falls within the quote unquote normal range, but you still feel exhausted. Maybe you're gaining weight, have brain fog because your body isn't actually making enough of the active thyroid hormones, or it isn't converting them properly or your cells aren't using them effectively.

Rachel: 5:09

So what should be tested then?

Mark: 5:11

This is why testing free T3 and free T4 is so crucial. Those are the hormones that are actually unbound, circulating and available for your tissues to use. T4 is the main storage form and T3 is the more potent active form. You need to see both Got it Free T3 and free. T4 is the main storage form and T3 is the more potent active form you need to see both Got it Free T3 and free T4.

Rachel: 5:28

And what about the autoimmune side of things? We hear about Hashimoto's quite a bit in relation to thyroid issues.

Mark: 5:34

Yes, hashimoto's thyroiditis. It's incredibly common, probably the most common cause of hypothyroidism, certainly in places like the US, and it's where your own immune system mistakenly attacks your thyroid gland.

Rachel: 5:46

Okay, and how does that relate to fatigue? If the TSH might still look okay?

Mark: 5:51

Well, what's really interesting and kind of sneaky is that the autoimmune attack can start years, literally years, before your TSH level goes significantly high enough to trigger a hypothyroidism diagnosis based on standard ranges.

Rachel: 6:03

Wow, years. Yeah, during that time, as the thyroid is being slowly, damaged to trigger a hypothyroidism diagnosis based on standard ranges.

Mark: 6:06

Wow, Years, yeah. During that time, as the thyroid is being slowly damaged, you might experience fluctuating symptoms periods of intense fatigue, maybe some weight gain, feeling cold, alternating sometimes with periods where you might feel a bit anxious or jittery, almost like hyperthyroidism, as the damaged gland releases stored hormone, so it can be confusing.

Mark: 6:24

Very confusing and this is precisely why testing thyroid antibodies, specifically anti-TPO and anti-TG antibodies, is so important. They're direct markers of that autoimmune attack. If those antibodies are elevated, it's a very strong indicator you're dealing with Hashimoto's, even if your TSH is still technically normal, and knowing that completely changes how you'd approach managing the fatigue and the underlying immune issue. It also makes you think about other things like gut health, because there's a strong gut thyroid connection.

Rachel: 6:53

Okay, that makes a lot of sense. So, beyond iron and thyroid, these sort of big hormonal players, sometimes the fatigue might boil down to like the basic building blocks the body needs to even make energy right, exactly Like if someone's struggling with brain fog, along with fatigue or maybe low mood, even some weird nerve sensations. What are the key micronutrients we should be thinking about?

Mark: 7:15

Absolutely. Think of it like this you can have fuel like iron for oxygen and the accelerator pedal working like the thyroid, but you also need the right spark plugs to actually ignite the energy.

Rachel: 7:27

Good analogy.

Mark: 7:28

Three huge ones for energy production and nerve function are vitamin B12, folate and vitamin D.

Rachel: 7:33

Okay, b12, folate, vitamin D let's take B12 first and D let's take B12 first.

Mark: 7:37

Right, b12 and folate. They work together really closely. They're essential for making healthy red blood cells so there's an overlap with anemia there but also for DNA synthesis and, really importantly, for a process called methylation.

Rachel: 7:48

Methylation. Okay, what does that do for energy?

Mark: 7:56

Methylation is fundamental. It's involved in gosh hundreds of processes, including making neurotransmitters, detoxifying hormones and critically turning genes on and off and producing energy at the cellular level. So a deficiency in B12 or folate can lead directly to fatigue, weakness, sometimes even neurological symptoms like numbness, tingling or memory problems, even if your iron levels are totally fine.

Rachel: 8:15

And I've heard, b12 absorption can sometimes be an issue for people right, even if they eat enough B12-rich foods. Oh, issue for people right, like even if they eat enough B12 rich foods?

Mark: 8:22

Oh, definitely, it's quite common. Things like low stomach acid, using acid blocking medications like PPIs, long term gut issues like Crohn's or celiac disease, even certain genetic variations, can really impair your ability to absorb B12 from food or even standard supplements, and this is where standard testing can sometimes fall short. Again, just looking at serum B12 doesn't always tell you if the B12 is actually getting into the cells and doing its job.

Rachel: 8:48

What's a better way to check?

Mark: 8:50

Often, clinicians will also look at a marker called methylmalonic acid or MMA. Mma levels tend to go up when your body doesn't have enough functional B12 at the cellular level, so it gives you a more functional picture of B12 status.

Rachel: 9:04

MMA. Good to know. And what about folate? Is there a better way to test that too?

Mark: 9:08

Similarly for folate. Yeah, Serum folate can fluctuate a lot depending on what you ate recently. A more stable long-term indicator is often considered to be RBC folate, or red blood cell folate. It reflects your body's folate stores over the lifespan of your red blood cells about three months.

Rachel: 9:23

Okay, rbc folate Got it. And then the third one you mentioned was vitamin D. That seems to come up everywhere these days.

Mark: 9:29

It really does, and for good reason. It acts much more like a hormone than just a simple vitamin. It's involved in immune function, bone health, obviously, mood regulation and critically for this conversation the actual function of your mitochondria. Those are little powerhouses inside your cells that generate energy.

Rachel: 9:46

Right, the energy factories.

Mark: 9:48

Exactly so. Low vitamin D levels are strongly linked to fatigue, muscle aches and pains, weakness and even symptoms of depression, and deficiency is incredibly widespread.

Mark: 10:00

Especially for those of us not living near the equator and even symptoms of depression and deficiency is incredibly widespread, Especially for those of us not living near the equator. Precisely If you live in northern latitudes, have darker skin pigmentation or just don't get much safe sun exposure, your risk is much higher. But the good news is, like B12 and folate, once you identify a vitamin D deficiency, the test you want is 25-hydroxyvitamin D. It's usually pretty straightforward to correct with appropriate supplementation and monitoring. These are foundational pieces for energy.

Rachel: 10:26

Foundational. Yeah, okay, so we've covered iron, thyroid, key vitamins. But even if all those levels look pretty good, sometimes it feels like just well, modern life itself is the biggest energy drain. Let's talk about stress. How does chronic stress really impact energy beyond just feeling, you know, mentally frazzled?

Mark: 10:43

Oh, it's profound. It's absolutely not just in your head your body's stress response system, which is mainly governed by the hormone cortisol produced by your adrenal glands.

Rachel: 10:53

Right Cortisol.

Mark: 10:54

That system is deeply, deeply connected to your energy regulation, your blood sugar balance, your immune function, sleep cycles, everything.

Rachel: 11:02

So what happens when that system gets out of whack from, say, constant pressure?

Mark: 11:07

Well, when cortisol is out of balance and that could mean it's consistently too high, or maybe it drops too low, or maybe the daily rhythm is just completely off-den your energy levels will absolutely suffer.

Rachel: 11:18

How so? What does that feel like?

Mark: 11:19

Initially, with acute or early chronic stress, cortisol might stay elevated. That can lead to that classic feeling of being wired but tired. You might have trouble falling asleep, feel anxious, maybe crave sugar or salt.

Rachel: 11:31

Yeah, I know that feeling.

Mark: 11:32

But if that stress continues relentlessly over a long period, the system can start to sort of fatigue itself becomes less responsive. Period the system can start to sort of fatigue itself becomes less responsive. This is sometimes referred to informally as adrenal fatigue, though in a more accurate term is HPA axis, dysregulation, hypothalamic, pituitary adrenal axis.

Rachel: 11:50

HPA axis dysregulation Okay.

Mark: 11:53

In this later stage, cortisol production might actually dip, especially at times when it should be higher, like in the morning. This leaves you feeling profoundly flat, foggy-headed, unmotivated, just completely burned out and unable to cope with even minor stressors.

Rachel: 12:10

So it's not just about how much cortisol you have overall, but also the pattern throughout the day.

Mark: 12:15

Exactly. That's the crucial part that a single blood draw often misses. A one-time blood cortisol test, usually done in the morning, only gives you a tiny snapshot Right. What's much more revealing is doing a diurnal cortisol panel. This typically involves collecting saliva or sometimes dried urine samples at several points throughout the day, like upon waking, maybe mid-morning, afternoon and before bed.

Rachel: 12:36

Okay, tracking a rhythm.

Mark: 12:38

Precisely. It shows you your cortisol rhythm. Is it peaking nicely in the morning to help you wake up and feel energized. Does it gradually decline throughout the day? Does it reach its lowest point at night so you can sleep restfully? That natural curve is vital for sustained energy.

Rachel: 12:52

And if that curve is off, like flat or high at night.

Mark: 12:55

If it's off, maybe it's flatline low all day, maybe it spikes erratically or stays high at night. That directly correlates with symptoms like persistent fatigue, insomnia, afternoon energy crashes or feeling oddly wired when you should be winding down. A diurnal cortisol test can provide really profound insights if stress seems like a major factor in your fatigue.

Rachel: 13:16

That makes a lot of sense, okay. And finally, there's one more big area you mentioned that can really drive your fatigue. That makes a lot of sense, okay. And finally, there's one more big area you mentioned that can really drive chronic fatigue, and it's one maybe people don't immediately connect unless they have a specific diagnosis Blood sugar.

Mark: 13:28

Yes, Blood sugar dysregulation. This is huge and often flies under the radar for a long time. We're not just talking about full-blown diabetes here. Many, many people experience significant fatigue, brain fog, irritability and those intense energy crashes because of underlying insulin resistance, often years before their blood sugar levels rise high enough for a type 2 diabetes diagnosis.

Rachel: 13:50

Insulin resistance. Can you break that down quickly? How does that cause fatigue?

Mark: 13:54

Sure. So normally when you eat carbohydrates, your blood sugar goes up. Your pancreas releases insulin which acts like a key, unlocking your cells to let that sugar in for energy. Okay, with insulin resistance your cells become well resistant to that key. They don't respond as well to insulin's signal, so sugar struggles to get into the cells where it's needed for fuel.

Rachel: 14:16

Ah, so the fuel isn't getting delivered properly.

Mark: 14:18

Exactly, and your pancreas tries to compensate by pumping out more and more insulin to try and force the doors open. This leads to high insulin levels in the blood and that causes problems. It causes a cascade of problems. First you get this roller coaster effect. Maybe a big surge of sugar gets into the cells eventually, or the high insulin drives blood sugar down too low later on. This causes those classic symptoms feeling exhausted after meals, intense cravings for sugar or carbs, that dreaded 3 pm energy slump the slump, yes and brain fog too, because your brain relies heavily on stable glucose. What's really critical to understand here is that your fasting glucose, the standard test, and even your HbA1c, which measures average blood sugar over about three months, those can both look perfectly normal for years, maybe even a decade, while this underlying insulin resistance and high insulin situation is brewing and making you feel terrible.

Rachel: 15:12

Wow, so those standard tests aren't catching the early problem.

Mark: 15:16

Often not the earliest signs. No, the real early warning sign is often elevated fasting insulin.

Rachel: 15:20

Is fasting insulin.

Mark: 15:22

If your fasting insulin level is high, even with normal fasting glucose, it's a huge red flag. It tells you your body's already working way too hard compensating to keep your blood sugar stable. That chronic metabolic effort is incredibly taxing and is a major, major driver of fatigue for so many people.

Rachel: 15:39

So if someone suspects blood sugar issues might be part of their fatigue puzzle, they should ask for fasting insulin specifically, not just glucose or A1C.

Mark: 15:47

Absolutely. Insist on it. Don't just check fasting glucose and A1C. Add fasting insulin to that panel. It provides such valuable information about your metabolic health and can be a complete game changer in understanding persistent fatigue cravings and energy instability.

Rachel: 16:03

That's incredibly helpful. Ok, so we've covered a lot of ground here Iron, thyroid vitamins, cortisol, blood sugar. So, pulling it all together, what's the main takeaway? For someone listening who just feels tired all the time? Yeah, what does it all mean for you, right, exactly, I think the core message has to be feeling exhausted constantly. Isn't something you just have to accept or normalize. It's not just about needing more sleep, although sleep is important, or, you know, doubling down on caffeine. Fatigue, especially when it's chronic like this is, is really a symptom. It's your body sending up a flare signaling that something deeper needs attention.

Mark: 16:40

Beautifully put. It's a signal. And just to quickly recap the areas we touched on we talked about optimizing iron stores, looking beyond just hemoglobin to ferritin. We discussed getting a complete thyroid picture, including free T3, free T4, and thyroid antibodies, not just TSH. We covered foundational nutrients like B12, folate and vitamin D and why functional testing might be needed Yep. We talked about assessing your stress response with diurnal cortisol testing to understand your HPA axis function. And finally, looking beyond basic glucose checks to fasting insulin to catch early blood sugar dysregulation and insulin resistance.

Rachel: 17:16

That's a great summary.

Mark: 17:18

And the key point through all of this is that the answers, or at least the crucial clues, are so often found in your labs. Getting the right test done gives you real, objective data.

Rachel: 17:28

Yeah.

Mark: 17:28

And that knowledge is incredibly empowering. It allows you to stop the guesswork and actually start a targeted journey towards healing, towards figuring out your specific puzzle and, ultimately, reclaiming your energy.

Rachel: 17:39

Absolutely, it puts you back in the driver's seat. So maybe a final thought to leave everyone with building on that idea of taking action. If your body is sending that signal, that fatigue flare you mentioned, what deeper insights, what missing pieces of your unique energy puzzle might your own lab results reveal?

Mark: 17:57

It's a powerful question to ask yourself.

Rachel: 17:59

It really is. Keep asking those questions, keep seeking those answers and keep diving deep into understanding your own health.

Nicolette: 18:10

Thanks for tuning into the Health Pulse. If you found this episode helpful, don't forget to subscribe and share it with someone who might benefit. For more health insights and diagnostics, visit us online at wwwquicklabmobilecom. Stay informed, stay healthy and we'll catch you in the next episode.