Can low ferritin make you tired with a normal blood count?

The blood count came back normal, the GP said everything looked fine, and by 3pm the eyelids are still heavy. A nap helps for an hour.

Yes, it can, and iron is one of the first things worth checking: ferritin is the iron your body keeps in store, and it can run low while haemoglobin, the figure on a standard blood count, still looks normal. At Medical Express Clinic, the Anaemia & Iron Profile shows the full iron picture for £126.25 plus the £50 blood draw, with results in 1 working day. You can have it taken at 117a Harley Street without an appointment, and a doctor can go through it with you the next day if you choose. Book a private blood test in London or read on for what each symptom tells us.

Why a normal blood count can miss it

Think of iron as a bank balance. Haemoglobin is the cash in your pocket today; ferritin is the savings behind it. The body protects the cash for as long as it can, so the savings can empty well before haemoglobin falls.

Tiredness that lingers after sleep

Waking tired, flagging mid-afternoon, needing more rest for the same day. Iron carries oxygen to muscle and brain, so a thin supply feels like running on a low battery. Our guide to tiredness and its many causes covers the wider list; this page asks whether low stores are behind it.

Breathlessness on the stairs

Needing a moment at the top of a flight that was easy last year is a classic sign. Less iron means less oxygen per heartbeat, so the heart and lungs work harder. The GP listens to your chest and heart, checks pulse and blood pressure, and uses the iron results to see whether stores explain it.

Hair shedding

More hair in the brush or shower drain, usually a few months after stores started to fall. Thyroid function can thin hair too, so if that makes sense for you, the doctor can add a thyroid function test from the same sample.

How a GP here reads your ferritin

NICE CKS states that a serum ferritin below 30 micrograms/L confirms iron deficiency. It also says ferritin is difficult to interpret when infection or inflammation is present, because levels can be high even with iron deficiency. For that reason a GP at Medical Express Clinic never reads ferritin alone. We read it with transferrin saturation, which shows how much of the blood's iron-carrying capacity is in use, with CRP, a marker of inflammation, and with the full blood count, set against your periods, diet and symptoms.

That reading is what the £150 GP appointment gives you. There is no fixed time limit, so questions about the result, the cause and the next step all get answered. It is charged on top of the blood test. If the picture shows low stores, the usual advice is to test first, then treat, and a doctor can recommend iron treatment that suits you. For a result from elsewhere, our guide to an abnormal blood test result explains what a GP review looks at.

Finding the reason, once ferritin is low

Low stores are a finding, and the next question is where the iron went. The GP asks about your periods, your diet and whether you give blood, because each can account for it. Poor absorption is another cause, so a coeliac blood test (tTG IgA, £86.25, results in 3 days) can be added to the same sample. For men, and for women whose periods have stopped, NICE CKS advises looking for a cause in the gut, so the GP arranges that promptly. Black or tarry stools, blood in the stool or weight loss you can't explain are reasons to come in sooner rather than later.

Heavy or long periods lose iron every month, and diet may struggle to replace it. Our women's health team can look at them in the same building. If a gut cause is suspected, the GP refers you to a specialist they know, and we charge nothing for the referral. The GP also sets a repeat test date, so the change is measured rather than guessed.

What the iron test costs at Harley Street

Ferritin alone is £68.75. The Anaemia & Iron Profile is £126.25 and covers iron, total iron-binding capacity (TIBC), ferritin and transferrin saturation, with results in 1 working day. Each is charged with the £50 blood draw. Our other commonly requested blood tests are listed online, and the wider blood test profiles suit a broader check.

One visit, one building

Blood is taken at 117a Harley Street seven days a week. Your sample reaches the lab the same day, and the turnaround clock starts there. If the GP thinks a thyroid test (from £100) or a full blood count would help, it can be added from the same sample, so you need only one needle. Medical Express Clinic has practised at 117a Harley Street since 1984 and was London's first private walk-in clinic.

For the laboratory side of iron studies, Blood London explains each marker in ferritin and iron studies explained.

Ready to go through your result with a doctor? Book a GP appointment at 117a Harley Street for £150.