"Your Bloods Are Fine." Then Why Are You Still Exhausted?

Imagine going to your GP feeling utterly drained, struggling to get through the day, and asking for blood tests, only to be told everything looks normal. No explanation, no next steps, just "your bloods are fine." You leave feeling relieved there's nothing seriously wrong, but no closer to understanding why you feel the way you do.

If this sounds familiar, you're not alone, and you're not imagining your symptoms. The gap comes down to a simple but important distinction: "normal" on a lab report and "optimal" for how you actually feel are not always the same thing. Understanding that difference can be the key to finally getting answers.

Why "Normal" Doesn't Always Mean Optimal

Again, if your standard bloods look normal is it not time to do a deep dive and check the many other available markers that are more likely able to help sign post you to what’s going on. 

Standard reference ranges are built from a wide population, which includes plenty of people who are unwell, undiagnosed, or simply not thriving. Falling inside that range only tells you that you're unlikely to have a diagnosable disease right now. It doesn't tell you whether your levels are actually supporting how you want to feel day to day.

This is where the "reference range" and the "functional range" differ:

• The reference range is used to screen for disease. It's intentionally wide.

• The functional range is a narrower band associated with people who report feeling genuinely well, not just disease-free.

Both have their place, but relying on the reference range alone can mean real, treatable patterns get missed.

Exhaustion: A Common Example: Ferritin

Ferritin is your body's iron storage marker, and it's a good illustration of this gap. Many labs flag anything above roughly 15 ng/mL as "normal" for women. But research and clinical experience suggest that levels below 50 ng/mL are commonly linked to fatigue, hair thinning, and poor exercise tolerance, even when the number is technically within range.

A result of 20 ng/mL might come back as "fine" on your report, while still leaving you well short of where your body needs to be to feel well. (If you're looking to support your iron intake through food, this week's [Summer Veg & Beetroot Salad with Figs] is naturally rich in iron.)

Another Example: Thyroid (TSH)

Conventional medicine typically checks two thyroid markers: TSH and T4. If both fall within the standard "normal range," you're usually told your thyroid looks fine.

But according to functional medicine, that picture is incomplete. A TSH of over 2.5 is already moving into a range associated with possible hypothyroidism, even though many labs won't flag it until much higher. Symptoms linked to this include fatigue, weight gain and difficulty losing weight, feeling cold, constipation, and difficulty concentrating or brain fog.

T4 also isn't the full story. It's mostly an inactive hormone that needs to convert into T3, the active form your body actually uses. If that conversion isn't happening efficiently and T3 comes back low, you likely have an underactive thyroid, even if TSH and T4 look acceptable on their own.

There are also thyroid antibodies, which conventional testing often doesn't include at all, but which can reveal autoimmune activity long before standard markers shift. Two people can have "normal" TSH results and still be in very different places when it comes to how their thyroid, and their body, is actually functioning.

Why This Gap Gets Missed

A few reasons this pattern is so common:

• Reference ranges are built for detecting disease, not optimising wellbeing

• A single marker in isolation can look "fine," while a fuller picture across several markers tells a different story

• Appointments are often too short to dig into the context behind a number

• Symptoms like fatigue, brain fog, or low mood are easy to attribute to stress or ageing rather than investigated further

What You Can Do

• Ask for your actual numbers, not just "normal" or "abnormal." Understanding where you sit within the range matters.

• Look at markers together, not in isolation. A ferritin in the low-normal range alongside a borderline TSH tells a more complete story than either alone.

• Track how you feel alongside your results. Persistent symptoms despite "normal" labs are a signal to look deeper, not a sign it's "all in your head."

• Consider a functional medicine review if standard testing keeps coming back clear but symptoms persist. This looks at the fuller picture, including markers not always covered in a routine panel.

In Summary

• "Normal" blood results are based on a wide population reference range built to screen for disease, not to define optimal health

• Markers like ferritin and TSH can sit inside the "normal" range while still being associated with real symptoms

• Persistent symptoms despite "normal" labs are worth investigating further, not dismissing

• A functional medicine approach looks at the fuller picture across markers, not just pass/fail results

A Final Word

If you've been told everything looks fine but you don't feel fine, that gap is worth taking seriously. Your results deserve a closer look, not just a box ticked.

If you'd like a deeper look at what your blood results might really be telling you, book a free 15-minute discovery call with me today.

Book a Free 15 Minute Discovery Call