Ferritin Only or a Full Iron Panel? Choosing the Right Iron Blood Test

Ferritin is the most commonly requested iron marker, but on its own it can mislead. Ferritin reflects your iron stores. Inflammation or infection can push it up, though, and that can hide a real deficiency. That’s why a combined iron blood test is often more useful.

Swift’s Advanced Iron blood test costs £120 and covers 23 biomarkers. It pairs iron studies with a full blood count, vitamin B12, folate and high-sensitivity CRP, so a “normal” ferritin can be read in context.

Who should consider an iron test

Low iron is one of the most common nutritional problems in the UK. Testing is worth thinking about if you:

• feel tired, weak or short of breath;
• have heavy periods;
• are pregnant or have recently given birth;
• follow a vegetarian or vegan diet;
• do a lot of endurance exercise;
• give blood regularly;
• have a condition that affects absorption, such as coeliac disease.

Low iron symptoms in women

Women are more likely to run low on iron because of periods, pregnancy and breastfeeding. Common low iron symptoms in women include:

• tiredness and lack of energy;
• shortness of breath with light activity;
• pale skin;
• headaches;
• noticeable heartbeats (palpitations);
• thinning hair or brittle nails.

These symptoms overlap with many other conditions, so an iron blood test is the way to confirm whether iron is the cause.

The three levels of iron test

Test	What it includes	Best for
Iron Status (£60)	Ferritin, iron and transferrin saturation	A simple check or monitoring known low iron
Advanced Iron (£120)	Full blood count, ferritin, iron, TIBC, transferrin, transferrin saturation, folate, B12 and high-sensitivity CRP	Tiredness, suspected anaemia, heavy periods or unclear past results
Tired All the Time (£160)	Iron alongside thyroid, vitamin D, HbA1c and other markers	Tiredness with no obvious cause

If you only want a quick check, the Iron Status blood test covers the core markers. If tiredness is your main concern and the cause isn’t clear, the Tired All the Time blood test looks more widely.

Why the extra markers matter

The Advanced Iron test includes markers that change how your iron results are read:

• Full blood count. This shows whether you’re actually anaemic. The size of your red blood cells gives clues to the cause: small cells suggest iron deficiency, while large cells point towards B12 or folate deficiency. Our guide to the full blood count explains each value.
• CRP (C-reactive protein). This flags inflammation, which can falsely raise ferritin.
• B12 and folate. These catch the other common nutritional causes of anaemia.
• Transferrin and TIBC. These show how much iron your blood can carry and how much of that capacity is being used.

Together, these markers help you avoid two common mistakes: missing low iron because ferritin looks normal, and assuming tiredness is always caused by iron.

Preparing for your test

• If you take iron supplements, ask your clinician whether to pause them before the test, as they can affect serum iron. Never stop prescribed treatment without advice.
• Morning appointments are often recommended for iron tests, because serum iron changes through the day.
• Follow any fasting instructions given when you book.

When to see a GP first

Iron deficiency without an obvious cause, such as heavy periods, needs medical assessment. This is especially important for men and for women after the menopause, because it can be a sign of blood loss from the gut. Use a private result as the starting point for that conversation with your GP, not as a replacement for it.

Clinic or home collection

You can view the 23-marker iron test and book at clinics in Billericay, Basildon, Thurrock, Maldon, Brentwood, Chelmsford, Bromley or Sunbury. Home visits are available across Essex, Bromley and Surrey. Use the clinic finder to choose a location.

Reading your ferritin level and iron results

Iron results make most sense when the markers are read together:

• Low ferritin with low transferrin saturation usually points to iron deficiency.
• Normal or high ferritin with raised CRP may hide low iron, because inflammation pushes ferritin up.
• High ferritin with high transferrin saturation can suggest iron overload and needs GP follow-up.

Your report shows the laboratory’s reference ranges. Take any result outside the range to your GP, who can look at it alongside your symptoms and history.

Frequently asked questions

Is ferritin enough to check iron levels?

Often not, because inflammation can raise ferritin. CRP and a full blood count add important context.

What is the difference between Iron Status and Advanced Iron?

Iron Status covers three core markers. Advanced Iron adds a full blood count, B12, folate, TIBC, transferrin and high-sensitivity CRP, for 23 biomarkers in total.

Can I do an iron test at home?

Yes. Swift offers home visits with a venous blood draw in covered areas.

Should I stop iron tablets before testing?

Ask your clinician. Don’t stop prescribed treatment without advice.

What should my iron levels be?

Ranges vary by laboratory, age and sex. Your report shows the reference range used.

Is there a ferritin blood test near me?

Swift clinics cover Essex, Bromley and Sunbury, with home visits in covered areas.

Book your iron test

If you’d like a thorough iron check, book Swift’s Advanced Iron blood test at a clinic or at home.