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Health Check

Ferritin – The body's iron stores

Ferritin is the test that shows how large your body's iron stores are. It is most often taken for fatigue, hair loss, dizziness, or heavy menstruation, and is included in most broad health checks along with haemoglobin and iron status.

What is Ferritin?

Ferritin is a protein that stores iron in the liver, spleen, and bone marrow. The level in the blood reflects how much iron is in storage, unlike haemoglobin, which shows how much iron is currently being used in the red blood cells.

Why is Ferritin measured in a health check?

Iron deficiency can exist long before the blood count drops. Ferritin therefore catches deficiency earlier than haemoglobin alone and is also used to monitor how iron stores are replenished during treatment.

High and low values

High value: High values are seen in inflammation, infection, liver impact, high alcohol consumption, and in iron overload. Since ferritin rises during inflammation, it is often interpreted together with CRP.

Low value: Low values indicate empty iron stores, which can cause fatigue, shortness of breath on exertion, headaches, and poorer recovery during exercise.

Reference ranges differ between laboratories, sexes and ages and are stated in your result. The information here does not replace medical assessment.

How ferritin is measured in a health check

Ferritin is analysed from a standard venous blood sample, usually taken from the crook of the arm, alongside the rest of the health check. You don't need to fast specifically for ferritin, but if the health check also includes blood lipids or fasting glucose, fasting applies to the whole sample — in that case it's simplest to book a morning appointment and drink water as usual.

If you've had an infection, a fever, or a heavy training session in the past few days, ferritin can be temporarily higher than normal, since it's what's known as an acute-phase protein. If you want a value that reflects your everyday iron stores, it's reasonable to wait about one to two weeks after an infection. If you're taking iron supplements, mention this when interpreting the result, since ongoing treatment raises the value.

Who should check their ferritin?

Iron deficiency is one of the most common reasons people order a health check with a blood test. The deficiency develops slowly and is first noticed as a vague fatigue that doesn't improve with sleep. Groups at increased risk check their ferritin more often than others.

  • People who menstruate, especially with heavy or frequent bleeding
  • Pregnant women and those who have recently given birth, whose iron needs increase sharply
  • Endurance athletes and people who train hard several times a week
  • Vegetarians and vegans, since iron from plant sources is absorbed less efficiently
  • Blood donors and people who have recently had surgery
  • People with gastrointestinal disease, such as coeliac disease or inflammatory bowel disease

How ferritin is interpreted alongside other tests

A single ferritin value rarely tells the whole story. In a broad health check it's interpreted together with haemoglobin (Hb), MCV, transferrin, iron and CRP. Low ferritin combined with low haemoglobin points to iron deficiency anaemia. Low ferritin with normal haemoglobin means the stores are being depleted but the haemoglobin hasn't yet been affected — this is exactly the early stage a health check is good at catching.

If both ferritin and CRP are elevated, inflammation can mask a genuine iron deficiency, and the picture then needs to be supplemented. Persistently high ferritin values without explanation should always be assessed by a doctor, since they can be linked to liver impairment, high alcohol consumption or hereditary iron overload.

How often should the test be repeated?

With normal values and no symptoms, a check every other year as part of a regular health check is usually enough. If you've been diagnosed with iron deficiency and are being treated with iron supplements, the value is usually followed up after about three months, since the stores take time to refill even once haemoglobin has already normalised. If tiredness persists despite normal ferritin, the next step is usually to look at the thyroid, B12, folate and blood glucose — markers included in the broader health checks.

Frequently asked questions about Ferritin

What does low ferritin mean?

Low ferritin means that iron stores are empty or nearly empty. It is the most common cause of iron deficiency and can cause fatigue and reduced stamina even when the blood count is still normal.

Can ferritin be high without having too much iron?

Yes. Ferritin rises during inflammation, infection, and liver impact. Therefore, a high ferritin level is interpreted together with CRP and liver tests before concluding that it is an iron overload.

Do I need to fast before a ferritin test?

No, ferritin is not affected by food. If the test is taken as part of a health check that also includes glucose and blood lipids, fasting may still be required for those tests.

Which health checks include ferritin?

Ferritin is included in Labkollen's broad health checks as well as in packages focusing on fatigue, iron, and blood counts. All tests containing the marker are listed further down on this page.

How quickly does ferritin rise after starting iron supplements?

Haemoglobin often responds within a few weeks, while the iron stores — and thus ferritin — take considerably longer. Follow-up testing is therefore usually done after around three months of treatment.

Can you have iron deficiency despite normal ferritin?

Yes. In the presence of inflammation, ferritin can appear normal despite empty stores. CRP, transferrin saturation and a full blood count are then used together to get an accurate picture.

Is ferritin included in a standard health check with a blood test?

Ferritin is included in most broad health checks and in all packages focused on fatigue and iron status. Which tests include the marker is listed further down the page.

Health checks that include Ferritin

Ferritin is included in 10 of Labkollen's health checks. Analysis name in the result: S-Ferritin.

  • Man +

    49 markers

    Labkollens mest omfattande kontroll för män – inklusive testosteron, PSA och hjärt-kärlmarkörer.

    2 195 krMed prenumeration (årlig hälsokontroll): 1 756 kr

    See the test

  • Kvinna +

    44 markers

    Labkollens mest omfattande kontroll för kvinnor – inklusive järnstatus, sköldkörtel och hormoner.

    2 195 krMed prenumeration (årlig hälsokontroll): 1 756 kr

    See the test

  • Standard

    37 markers

    Bred hälsokontroll över blodsocker, blodfetter, blodvärde, lever, njurar, sköldkörtel och vitaminer.

    1 895 krMed prenumeration (årlig hälsokontroll): 1 516 kr

    See the test

  • Gravid

    26 markers

    Kontroll under graviditet – blodvärde, järn, sköldkörtel, vitaminer och hCG.

    1 199 krMed prenumeration (årlig hälsokontroll): 959 kr

    See the test

  • Vitamin- och mineralkollen

    18 markers

    D-vitamin, B12, folat, järn och mineraler för dig som vill kolla näringsstatus.

    1 199 krMed prenumeration (årlig hälsokontroll): 959 kr

    See the test

  • Uthållighetssport

    16 markers

    För löpare, cyklister och simmare – järnstatus, energiomsättning och återhämtning.

    1 599 krMed prenumeration (årlig hälsokontroll): 1 279 kr

    See the test

  • Lagsport

    16 markers

    För lagidrottare – energi, järn, återhämtning och stresshormon.

    1 599 krMed prenumeration (årlig hälsokontroll): 1 279 kr

    See the test

  • Kampsport

    15 markers

    För kampsportare – återhämtning, hormoner, inflammation och järn.

    1 599 krMed prenumeration (årlig hälsokontroll): 1 279 kr

    See the test

  • Gymnastik och konståkning

    14 markers

    För teknikidrotter – benhälsa, järnstatus, sköldkörtel och tillväxtmarkörer.

    1 599 krMed prenumeration (årlig hälsokontroll): 1 279 kr

    See the test

  • Järnkollen

    10 markers

    Full järnstatus vid trötthet, blekhet eller rikliga menstruationer.

    549 krMed prenumeration (årlig hälsokontroll): 439 kr

    See the test

Unsure which test you need? Start the test guide

Guides covering Ferritin

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Responsible for the content: Mathias Khemiri, Oftamed Sverige AB.

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