What is iron deficiency anaemia?

What is iron?

Iron is a mineral (a type of micronutrient) that you get from your diet.

What does iron do?

Iron is part of haemoglobin, a protein in red blood cells. Haemoglobin helps carry oxygen from your lungs to the rest of your body.

Iron also plays an important role in many other bodily functions, like wound healing.

How to test your iron levels

There are several blood tests that can show you if you have enough iron. They are:

• Haemoglobin: This is the protein in red blood cells that carries oxygen.
• Serum iron: This shows how much iron is in your blood currently, which fluctuates throughout the day.
• Ferritin: This indicates how much iron the body has in storage.
• Total iron-binding capacity (TIBC): This measures how effectively proteins, such as transferrin, can carry iron in your blood.
• Transferrin saturation: The amount of transferrin that is currently carrying iron.
• Unsaturated iron-binding capacity (UIBC): The amount of iron-binding sites on transferrin that aren't bound to iron.

Performing just one of these tests has some drawbacks. For example, serum iron can change rapidly over time. Ferritin can be more consistent, but can rise if you’re sick or have an inflammatory condition, making your iron levels look higher than they are.

Testing multiple iron markers helps to build a more accurate picture of your iron status.

Normal iron levels and reference ranges

What are normal iron levels? Reference ranges are set by individual labs and depend on the equipment and testing method used, so two labs can report slightly different ranges for the same marker. That's why you won't find a single chart of ranges here.

The range that matters is the one reported in your blood test results. It will show what that lab considers normal for each marker, and that's the comparison to make.

It's also important to pay attention to a doctor's report alongside your result. For example, ferritin rises with inflammation and infection, which is why WHO guidance recommends interpreting it alongside markers of inflammation.

What happens if you don’t get enough iron?

When you don’t get enough iron from food, your body will first use its own iron stores. These stores can last for some time, covering temporary gaps in your diet.

But if the stores run out, iron levels in the blood start to drop. Eventually, haemoglobin levels drop too. Low haemoglobin means your cells can’t get enough oxygen.

What is iron-deficiency anaemia?

Anaemia is when your red blood cells don’t have enough haemoglobin to provide cells with oxygen. A range of things can cause anaemia, but a lack of iron is the most common cause. This is called iron deficiency anaemia.

It’s also possible to have iron deficiency without anaemia. This happens when iron levels in the blood are low, but your body is still maintaining normal haemoglobin levels. 

Iron deficiency without anaemia causes some of the same symptoms as iron deficiency anaemia and has the same treatments.

Symptoms of iron deficiency anaemia

A lot of people don’t realise they have iron deficiency anaemia, so it’s important to know the symptoms. Common signs include:

• extreme tiredness
• weakness
• skin that looks paler than usual
• a fast or irregular heartbeat
• dizziness
• shortness of breath

Other symptoms may include:

• cold hands and feet
• brittle nails
• hair loss
• slow wound healing
• headaches
• low mood
• difficulty concentrating
• lower quality sleep
• a tingling or crawling feeling in your legs
• a sore or smooth tongue
• strange cravings to eat items that aren’t food, like dirt, ice, or clay

The symptoms of iron deficiency anaemia can be subtle and easily missed. 

If you have any of these symptoms, it’s really important to check your iron levels. You can do so with Thriva’s easy, at-home blood testing. 

Causes of iron deficiency anaemia

Your iron levels can drop if:

• your diet is low in iron — vegans and vegetarians are sometimes low in iron
• you have a digestive condition, like coeliac disease or Crohn’s disease
• you have heavy periods
• you lose lots of blood during childbirth

It’s not as common, but other types of blood loss can lead to low iron levels, such as from an ulcer or cancer.

How to increase your iron levels

Tablets and supplements

If you have iron deficiency anaemia, a doctor may prescribe a course of high-dose iron tablets to get iron levels up.

To increase how much you absorb, it’s best to take the tablets:

• on an empty stomach
• at least 30 minutes before food
• or at least two hours after food, if you take them later in the day

If the tablets cause nausea, it may help to take them with food instead. 

Try to avoid tea, coffee, or milk within two hours of taking iron supplements, as these foods can stop you from absorbing them. Certain medications, such as antacids, can also interfere.

Some people take their iron with a source of vitamin C, such as fruit juice, to boost absorption. But a 2020 trial involving 440 adults found that iron supplements were just as effective with or without vitamin C, so this may not be necessary.

Taking another iron test after a few months can show you if supplements are working. If they aren’t, or the supplements are causing unpleasant side effects, a doctor may suggest an iron infusion instead. These work by delivering iron directly into a vein.

Food sources of iron

To maintain healthy iron levels, try to make sure you’re getting enough from your diet. Good sources of iron include:

• seafood like mussels, clams or oysters
• iron-fortified cereals
• red meat
• legumes like lentils, beans, soy, and peas
• pumpkin and squash seeds
• dark green leafy vegetables like kale, spinach, and watercress
• dried fruit like raisins and apricots

Some people need a daily iron supplement when they can’t get enough iron from food. It’s best to get advice from a health professional about whether this would be beneficial.

Takeaway

Having iron deficiency anaemia means your blood doesn’t have as much haemoglobin as it needs. The condition can lead to a range of symptoms, including fatigue, dizziness, and weakness.

There are several blood tests that can help diagnose iron deficiency. Together, they provide insights into how the body is using or storing iron, as well as whether you’re getting enough.

High-strength iron tablets or infusions can treat an iron deficiency. In some cases, doctors may suggest an ongoing maintenance dose to keep your levels healthy.