Anaemia and iron deficiency: how do we find out and what do we do?

What does anaemia mean?

The red cells of the blood carry oxygen to the whole body, and haemoglobin, the iron-containing protein inside them, carries the oxygen. When red cells or haemoglobin are low, we have anaemia. Its most common type is anaemia caused by iron deficiency: the body’s iron store has fallen and the body cannot make enough haemoglobin.

Symptoms

Mild or early anaemia often has no symptoms. When it does cause symptoms, the most common are these:

• Tiredness and weakness
• Headache, dizziness, especially on standing up
• A pounding heart
• Shortness of breath
• Pale skin
• Trouble concentrating

Less common symptoms: hair loss, brittle nails, mouth ulcers, a sore or red tongue, restless legs, and a craving for non-food things. None of these on its own proves anaemia; tiredness and dizziness have many other causes too.

How is it diagnosed?

With a blood test. The blood cell count (CBC) measures haemoglobin and red cells. If anaemia is found, other tests such as iron, iron-binding capacity and ferritin (the iron store) show whether the cause is iron deficiency. The CBC test alone does not say why. A change in these numbers can also be related to dehydration, heart disease or other causes.

Why must the cause be found?

Iron deficiency is “a result”, not the illness itself. Common causes:

• Loss of blood. Heavy or long periods, and bleeding in the digestive tract (from a stomach ulcer, inflammation of the oesophagus or bowel, haemorrhoids and, less often, a tumour). Sometimes long-term use of some painkillers or blood-thinning medicines is the background to digestive bleeding.
• Poor absorption in some digestive diseases such as coeliac disease and Crohn’s disease, or after some stomach operations.
• Low iron in the diet, for example on a strict vegetarian diet.
• Greater need, such as pregnancy and breastfeeding.

If the cause of the anaemia is digestive bleeding or another cause that is not treated, giving iron alone will not fix it. That is why, as well as the blood test, the doctor may ask for a stool test for hidden blood or other investigations.

Iron tablets: do not start them yourself

It may seem obvious to “buy an iron tablet” when you are tired and pale. But:

• Without a test you do not know whether you have anaemia, and whether the cause is iron or something else.
• Treating with iron does not remove the underlying cause, such as bleeding; the cause must be found separately.
• Whether iron is needed, what type, and for how long, is decided by the doctor after the test. After treatment starts, tests are usually repeated too.
• Iron supplements have side effects: nausea, constipation or diarrhoea, abdominal pain and darkening of the stool. If iron has been prescribed for you and you have side effects, talk to the doctor or pharmacist. If the stool turns dark, do not draw your own conclusion: if it comes with weakness, dizziness or abdominal pain, get checked immediately.
• Too much iron can be dangerous for children. If you have iron tablets at home, keep them out of children’s reach.

What does food do?

Food containing iron helps with prevention, but proven anaemia is usually not treated with food alone. Sources of iron: meat, chicken and fish, pulses and soy, dark leafy green vegetables, dried fruit and fortified grains. Vitamin C (citrus, tomatoes, kiwi) improves iron absorption; tea, coffee and dairy reduce it. If you find it hard to get enough iron from food, ask the doctor or a nutrition specialist for help.

When should I see a doctor sooner?

• Tiredness, paleness or a pounding heart has lasted more than a few weeks.
• Your periods are heavy and long.
• You have pain in the upper abdomen.

Black tarry or bloody stool must be seen the same day. If you vomit blood (even if the vomiting has stopped), or have severe shortness of breath, or have black tarry stool and with it you feel unwell, confused, pale or sweaty, call 115 (Iran’s emergency number) immediately. The details are in the section “When should I call urgently?”.