Problemas de salud
Iron deficiency anaemia
Revisado: 4 de octubre de 2026
Solo en inglés por ahoraHeavy periods are one of the most common causes of low iron. Learn the signs of iron deficiency anaemia, how it is tested and how it is treated.
What it is
Your body uses iron to make haemoglobin, the part of red blood cells that carries oxygen around your body. If you do not have enough iron, you cannot make enough healthy red blood cells. This is called iron deficiency anaemia. It is the most common type of anaemia. It is often caused by losing blood, or by pregnancy.
How periods can lower your iron
Losing a lot of blood with your period each month is one of the main reasons, because you lose iron with the blood. Other causes include bleeding in the stomach or bowel, for example from an ulcer or from taking aspirin or other anti-inflammatory painkillers (NSAIDs) regularly. A doctor will look for the cause, especially if your periods are not heavy, because hidden bleeding in the gut sometimes needs tests. Some conditions, such as coeliac disease or Crohn's disease, make it harder for your body to absorb iron. Not getting enough iron from food can also play a part, especially in pregnancy.
Signs to look out for
Common signs are tiredness and lack of energy, shortness of breath, a heartbeat you can feel (palpitations), paler skin than usual, and headaches. Some people feel dizzy or have cold hands and feet. Less common signs include hair loss, a sore tongue, itchy skin, ringing in the ears, and restless legs. Some people want to eat things that are not food, such as ice or paper (pica).
Tests
A doctor or nurse will usually arrange a blood test called a full blood count. This shows whether your red blood cells and haemoglobin are low. Other blood tests can check how much iron is in your blood and how much your body has stored (ferritin). Tell the doctor if your periods are heavy. Logging your bleeding in Ciclo can help you show how heavy your periods are.
Treatment
Iron tablets are the usual treatment. Take them as your doctor, nurse or pharmacist advises, and keep them out of sight and reach of children, because too much iron can be fatal for a child. It often takes 3 to 6 months to refill your iron stores. Drinking orange juice after a tablet may help your body absorb the iron. Try not to have tea, coffee, milk or other dairy foods around the same time. Side effects can include constipation or diarrhoea, tummy pain, heartburn, feeling sick and darker poo. Taking tablets with or soon after food may help. Sometimes iron is given through a drip into a vein, or a blood transfusion is needed.
When to get help
See a doctor or nurse if you think you might have anaemia, especially if your periods are heavy. Heavy means changing a pad or tampon every 1 to 2 hours, using two products at once, or periods lasting more than 7 days. If heavy periods are the cause, ask about treatment for them too. Get emergency help if you have chest pain, feel very short of breath, or have very heavy bleeding with dizziness or fainting.
This is general information, not a diagnosis. If you think your iron is low, see a doctor or nurse for a blood test.