Iron Blood Test, from our experts to you.
Dr Sam Rodgers MBBS, MRCGP

Chief Medical Officer

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What is iron and
why is it important?

Iron is an essential mineral that’s needed to make haemoglobin, a protein found in red blood cells that helps transport oxygen around your body. It also plays an important role in supporting your immune system, maintaining energy levels, and regulating body temperature. 


When your iron level is low, you can feel tired and be more susceptible to illnesses and infections. And a severe lack of iron could lead to iron deficiency anaemia, which causes fatigue, shortness of breath, and heart palpitations.

What can I learn from this
at-home iron blood test?

Our easy finger-prick iron test checks several biomarkers to give you a full picture of your iron levels. As the iron level in your blood fluctuates daily, based on the iron you get from your diet, this test also measures ferritin — a protein used to store iron in your body. Ferritin is almost always the best measure of your iron status as it’s more stable.

What causes
low iron levels?

Low iron levels are most commonly caused by blood loss, such as heavy periods or internal bleeding (often in the digestive tract). You're at greater risk if you regularly take steroids, blood thinners, or drugs like ibuprofen. Other causes of iron deficiency include pregnancy, a low-iron diet, or bowel conditions like coeliac disease and inflammatory bowel disease.

of the test

Ferritin levels may be raised with conditions such as infection, inflammation, liver or renal conditions, or chronic alcohol consumption. However, our test also checks an inflammatory marker (hs-CRP) to help distinguish between some of these causes.

What's Included?

Iron status
Select profile for more information

hs - CRP C-Reactive Protein (CRP) is an inflammation marker used to assess whether there is inflammation in the body - it does not identify where the inflammation is located. High Sensitivity CRP (CRP-hs) is a test used to detect low-level inflammation thought to damage blood vessels which can lead to a heart attack or stroke. When you suffer a serious injury or infection you experience significant inflammation around the site of injury - such as the swelling around a twisted ankle. Any injury like this will cause your CRP-hs to rise.
Iron Iron is a mineral that is essential for life. It is a component of haemoglobin, a protein in our red blood cells that is responsible for transporting oxygen around our body. If we don't have enough iron, our haemoglobin levels fall and we can't get sufficient oxygen to our cells. This can cause symptoms which include fatigue, dizziness, and shortness of breath. Serum iron is a very transient reading and can be influenced by the amount of iron-rich food in your diet in the days before your blood test. For this reason, iron is rarely looked at on its own, and is interpreted alongside other markers in an iron status test.
TIBC Total iron-binding capacity (TIBC) is a measure of the ability of your body to efficiently carry iron through the blood.
Transferrin saturation Transferrin is made in the liver and is the major protein in the blood which binds to iron and transports it round the body. This test measures how much this protein is 'saturated' by iron.
Ferritin Ferritin is a protein which stores iron in your cells and tissues. Usually, the body incorporates iron into haemoglobin to be transported around the body, but when it has a surplus, it stores the remaining iron in ferritin for later use. Measuring ferritin levels gives us a good indication of the amount of iron stored in your body.

How to prepare
for your test

Special Instructions

Prepare for your Iron Blood Test by following these instructions. Take this test when any symptoms of short-term illness have settled. Do not take biotin supplements for two days before this test, discuss this with your doctor if it is prescribed.

Frequently asked questions

What is a normal level of iron in the blood?

Your iron levels fluctuate daily according to your diet. For this reason, ferritin, a measure of your iron stores, is often a more useful marker of your iron status.

For everyone, a ferritin level less than 30 micrograms/L confirms iron deficiency. However, this threshold may be higher in people with chronic inflammatory conditions, where ferritin levels may be falsely raised.

What happens if my iron levels are too low?
If your iron levels are too low, your body may struggle to carry enough oxygen to the tissues. This can lead to iron deficiency anaemia and symptoms such as tiredness, low energy, and shortness of breath. Depending on the cause, you may require iron supplements or injections to bring your iron levels back into a healthy range.
What happens if my iron levels are too high?
Too much iron can also cause health problems. It may be caused by taking too many iron supplements, excess iron in your diet, or an inherited condition called haemochromatosis. Over time, excess iron is stored in your liver and other organs. This build-up can cause heart problems, joint pain, and liver disease. However, there are treatments which can reduce the amount of iron in your body and lessen the risk of long-term damage.
How can I improve my iron levels?

If your diet is contributing to low iron levels, you can try eating iron-rich foods like dark-green, leafy vegetables and meat (if it’s in your diet). Drinking citrus juices alongside a meal including green leafy vegetables can also help improve absorption.

If you eat a plant-based diet, read our guide on nutrition for more plant-based sources of iron. Sometimes, you may need a supplement to boost your levels, and you should carefully follow any treatment advice your GP gives you.

How can I test my iron levels at home?
We’ll send you everything you need to test your iron levels at home, including our easy finger-prick iron test kit and a pre-paid return envelope for your sample. Our at-home iron test includes a full lab analysis of your blood sample, doctor’s advice and any next steps.

What’s the difference between iron and ferritin?

The main difference between iron and ferritin is that iron is a mineral (present in the red blood cells that carry oxygen) and ferritin is a protein that stores iron and releases it when the body needs it. So, even though they aren’t the same, they work together.


Women and iron deficiency anaemia


Premenopausal women are at greater risk of iron deficiency compared to men due to pregnancy and menstruation. During pregnancy, you and your baby will need a lot more iron to make red blood cells, which can deplete your iron stores leading to anaemia. Heavy periods can also put you at risk of low iron levels due to blood loss, so it’s important to keep an eye on any symptoms of a deficiency. Read more about iron levels for women.


Iron overload syndrome


Raised iron in the blood can indicate haemochromatosis, an inherited condition that causes your body to absorb too much iron. A build-up of iron can cause symptoms like fatigue, joint pain, and muscle weakness. And if left untreated, this can lead to health issues including liver damage. Our Iron Overload (Haemochromatosis) Blood Test can help you check for the condition if you have a family member with haemochromatosis, or if you’re experiencing symptoms.