Over 50 and always tired? GPs highlight the one blood test patients forget to request

The waiting room was too warm, the sort of central heating that makes you drowsy even when you slept badly. Around you: a man with a crinkled newspaper, a woman in gym kit scrolling, an older couple quietly comparing appointment letters. You were there for the same reason as half the room, if not more: you are over 50, and you are always tired. Not sleepy-tired. Bone-tired. The kind that makes stairs feel steeper and evenings shorter.

Your GP listened, nodded, ordered some “routine bloods”. A week later, the receptionist said everything was “normal”. You tried stronger coffee, earlier bedtimes, a multivitamin from the chemist. Still tired. And in the blur of that appointment, there is one small blood test that often never gets mentioned unless you bring it up yourself.

The overlooked test GPs wish people knew to ask for

Most people think “iron test” or “full blood count” cover everything. They don’t. The quiet marker that many over‑50s miss is serum ferritin - essentially, your iron stores. Not just what is circulating today, but what is in the cupboard for tomorrow.

Full blood counts check your haemoglobin and red blood cells. They can tell your GP if you are already anaemic. Ferritin answers a different question: are you running out of iron before the anaemia even shows? You can have “normal” haemoglobin and still have very low ferritin, and that low reserve can feel like ageing on fast‑forward.

“Ferritin is the one I end up adding after the ‘normal’ bloods when someone is still utterly wiped out,” says Dr Amrita Kaur, a GP in Birmingham. “People assume we’ve checked it automatically, but often it isn’t on the first form unless there’s a clear reason.”

Ferritin doesn’t explain every case of fatigue, but for many in midlife it is the missing line on the results sheet - especially for women who have had years of heavy periods, anyone with a history of gut issues, or people who have quietly trimmed red meat from their diet without replacing the iron elsewhere.

What ferritin is really telling you

Think of haemoglobin as the taxis carrying oxygen around your body and ferritin as the taxi depot. You can have a decent number of taxis on the road today while the depot is nearly empty.

When ferritin drops, your body starts cutting back on non‑essentials to keep you upright. You get:

• Tired, even after a “full night’s sleep”
• Breathless faster on hills or stairs
• Heavy legs when you walk
• Brain fog, irritability, low mood
• Restless legs at night or strange crawling sensations
• Thinner hair, brittle nails, paler skin

None of those scream “iron” on their own. Together, especially in someone over 50, they can look a lot like “just getting older” or “a bit stressed”. That mislabel matters. If the story is ageing, you grit your teeth and push on. If the story is low iron stores, there is something to test, treat and track.

Ferritin can also run high in some conditions (inflammation, liver problems, certain metabolic issues), which is why it sits in a wider picture for your GP rather than a magic number to fixate on at home.

Why midlife makes ferritin more important

By 50, your body has a long back‑catalogue:

• Years of menstrual blood loss for many women
• Decades of acid reflux tablets, anti‑inflammatories or aspirin that may have gently bothered the gut lining
• Dietary shifts - less red meat, smaller portions, sudden “healthy” restrictions
• Silent gut conditions like coeliac disease or inflammatory bowel disease that blunt iron absorption
• Operations, injuries or donations that emptied the tank and never quite got topped up

Retirement or semi‑retirement can shift the picture too. You might move less, snack more and catch colds more easily. Fatigue blends into lifestyle, and nobody thinks to ask whether the iron cupboard has quietly emptied out.

Men are not immune. Slow internal blood loss from the stomach or bowel, often completely invisible, is a classic midlife culprit for iron‑store depletion in men and post‑menopausal women. In that group, low ferritin is a flag to look deeper, not just a prompt to hand over tablets.

How to talk to your GP about a ferritin test

You do not need the perfect speech. You need a clear story and a direct question.

Describe your fatigue in concrete terms: how far you can now walk, what time you start flagging, what you have had to give up. Mention anything that nudges the iron story:

• A history of heavy or prolonged periods
• Blood donations, past or recent
• Long‑term use of anti‑inflammatory painkillers, aspirin or acid‑suppressing medicines
• Gut symptoms (bloating, loose stools, heartburn, unexplained weight loss)
• Vegetarian or vegan diets, or very limited meat intake

Then say something like:

“I know my routine bloods were normal, but I’m still really struggling. Could we specifically check my ferritin - my iron stores - to make sure low stores aren’t being missed?”

Most GPs will understand exactly why you are asking. They may also want to check a full blood count again, inflammatory markers, vitamin B12, folate, vitamin D, and thyroid function at the same time. That is not a brush‑off; it is sensible, because fatigue is rarely just one thing.

If your practice uses online consultations, you can write this out calmly rather than trying to remember it in an eight‑minute slot. Let’s be honest: nobody brings a neat bullet‑point list to every appointment.

Reading your result without scaring yourself

Lab “normal ranges” differ slightly, but a few principles help:

• Very low ferritin (often under 15–30 µg/L, depending on the lab) usually confirms iron deficiency.
• Borderline or “low‑normal” numbers can still be associated with symptoms in some people, particularly if you have the classic signs.
• Very high ferritin needs a proper medical assessment; it is not simply “iron overload from a good diet”.

Do not start high‑dose iron supplements on your own without a diagnosis. They can upset your stomach, backfire if the cause is not iron deficiency, and mask more serious problems if you treat the number without finding out why it is low.

Work with your GP on three questions:

1. Is this definitely iron deficiency?
2. If yes, what is the likely cause?
3. What is the plan to replace stores and re‑check?

Sometimes that plan is tablets and a repeat blood test. Sometimes it is also a referral for gut checks, especially if you are over 50 and there is no obvious explanation.

Fatigue over 50: what else should be on the radar?

Ferritin is one piece of a much bigger jigsaw. If you are over 50 and always tired, GPs will usually think broadly:

• Thyroid function tests (TSH, free T4): an underactive thyroid is common and sneaky.
• Vitamin B12 and folate: low levels can drag your energy and cognition down.
• Vitamin D: linked to muscle weakness and low mood, especially in darker months.
• HbA1c: checks for diabetes and “pre‑diabetes”, both tied to heavy fatigue.
• Full blood count, kidney and liver function: basic but important background checks.
• Sleep and mood: depression, anxiety, poor sleep and sleep apnoea all flatten energy.

Ferritin slips through the cracks when everyone assumes “we did iron” the first time. In many standard panels, nobody actually did.

Here is one way to think about patterns:

Main feeling	Possible clue	Worth asking about
Heavy limbs, breathless on hills, pale, restless legs	Low iron stores, anaemia	Ferritin, full blood count
Slowed down, cold, weight creeping up	Underactive thyroid	Thyroid function tests
Pins and needles, tongue soreness, forgetfulness	B12 or folate deficiency	B12 and folate
Achy muscles, winter blues	Low vitamin D	Vitamin D level

This is not a self‑diagnosis chart. It is a conversation‑starter.

What you can do while you wait for answers

You cannot eat your way out of a severe iron deficiency, but your habits still matter. Between blood tests and follow‑ups:

• Build iron‑rich foods into meals if you eat them: lean red meat, dark poultry meat, liver in moderation.
• Use plant sources if you prefer: beans, lentils, chickpeas, tofu, dark green leafy vegetables, fortified cereals.
• Pair plant sources with vitamin C (tomatoes, peppers, citrus) to help absorption.
• Go easy on strong tea and coffee with meals; tannins can block iron uptake.
• Keep a simple symptom diary: note energy levels, breathlessness, headaches, sleep quality.
• Resist the urge to stack random supplements. More is not always better, and mixtures complicate blood results.

If your ferritin comes back fine, that information still helps. It lets you and your GP cross one thing off the list and look more seriously at thyroid, sleep, mental health, long‑term infections, medications or heart and lung health. An answer of “not iron” is still an answer.

Why this matters more than “just being tired”

Midlife fatigue is often brushed off as inevitable, especially for women juggling ageing parents, work and their own changing hormones. Men push through, telling themselves that slowing down is normal at 55. Up to a point, it is. But normal does not mean unchangeable.

“If you’re constantly exhausted and it’s changing what you can do, you deserve a proper work‑up - not a pat on the head,” says Dr Kaur. “Ferritin is tiny on the form, but picking it up can transform how someone feels.”

Think of this less as hunting for a miracle test and more as asking for a fair look under the bonnet. Your blood results are not a pass/fail mark on how well you are handling life. They are data. Ferritin is just one line of that data, easily forgotten, quietly powerful.

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FAQ:

• Is ferritin the same as an ‘iron level’ test? Not quite. A basic iron panel may look at iron circulating in your blood that day. Ferritin reflects your stored iron and often drops earlier, making it helpful for spotting problems before full anaemia sets in.
  
• Can I just buy iron tablets if I feel tired? It is safer to test first. Taking iron when you do not need it can upset your gut and hide more serious causes of low stores or high ferritin. Always discuss supplements with your GP or pharmacist.
  
• Will my GP automatically check ferritin if I say I’m tired? Sometimes, but not always. Practices vary, which is why clearly asking about ferritin - and why you’re concerned - can be helpful.
  
• If my ferritin is low, will tablets fix my energy straight away? Most people feel a gradual lift over weeks, not days. It takes time to rebuild stores and for your body to use that iron. Your GP will usually re‑check levels after a few months.
  
• What if all my tests, including ferritin, are normal but I’m still exhausted? Go back. Persistent, life‑changing fatigue deserves follow‑up. Your GP may explore sleep apnoea, heart or lung problems, chronic infections, mood disorders, or refer you to a specialist fatigue or sleep clinic.