Iron deficiency in women: why you might feel so tired and what to do
What is iron deficiency?
Your body needs iron to make haemoglobin, the part of red blood cells that carries oxygen. If your iron stores run low, you may eventually not be able to make enough healthy red blood cells — this is called iron deficiency anaemia.
You can also have low iron stores before you become anaemic. Some people have symptoms even at this stage, and a blood test that measures your iron stores can pick this up.
Common symptoms
- Tiredness and lack of energy that doesn't go away with rest
- Shortness of breath, especially when you're active
- Heart palpitations — a racing, pounding or fluttering heartbeat
- Pale skin, or paleness inside your lower eyelids
- Headaches and feeling dizzy or lightheaded
- Difficulty concentrating
- Hair thinning, brittle nails or a sore tongue
- Feeling cold, especially hands and feet
- Restless legs
- Craving non-food things such as ice, which is called pica
Tiredness has many possible causes, so it's worth getting checked rather than assuming it's low iron.
Why women are more at risk
- Heavy periods — the most common cause in women of reproductive age
- Pregnancy — your body needs much more iron to support the baby
- Diet — not getting enough iron, which can be more of a risk on vegetarian or vegan diets if you don't plan for it
- Problems absorbing iron, for example with coeliac disease or after some types of stomach surgery
- Blood loss from the gut, which can be caused by stomach ulcers, some medicines such as anti-inflammatory painkillers, or, less commonly, bowel conditions including cancer
- Frequent blood donation or intense endurance exercise
If you're past menopause or don't have periods, a doctor will usually want to investigate where the blood loss might be coming from.
How it's diagnosed
A doctor can arrange a blood test, usually a full blood count to check for anaemia and a ferritin test to check your iron stores. They'll also ask about your periods, diet, any digestive symptoms and other health issues, and may arrange further tests to find the cause.
Treatment and food sources
If you have iron deficiency, your doctor may recommend iron tablets or liquid. Common side effects include constipation, an upset stomach and dark poos. Ask how to take them to reduce side effects, and how long to continue — treatment often continues for a while after your levels improve, to rebuild your stores. Some people need iron given through a drip.
Treating the cause is just as important, for example managing heavy periods.
Good food sources of iron include:
- red meat, poultry and fish
- beans, lentils and chickpeas
- tofu
- dark green leafy vegetables
- dried fruit, nuts and seeds
- iron-fortified breakfast cereals and breads
Vitamin C, found in fruit and vegetables, helps your body absorb iron from plant foods. Tea and coffee can reduce absorption, so try to have them between meals rather than with them.
Why you shouldn't self-treat
It's tempting to buy iron supplements and see if they help, but get tested first. Supplements can mask a cause that needs investigating, and taking too much iron can be harmful. Some people have a condition that makes their body store too much iron.
Keep iron supplements out of reach of children — an overdose can be very dangerous for them.
When to see a doctor or get help urgently
See a doctor if you've been feeling tired for a while without a clear reason, or have other symptoms of iron deficiency, heavy periods, or changes in your bowel habits.
Get urgent help if you have chest pain, severe breathlessness, fainting, black or tarry poo, blood in your poo, or vomiting blood.
Frequently asked questions
Can heavy periods cause iron deficiency?
Yes. Heavy periods are the most common cause of iron deficiency in women of reproductive age. Treating the heavy bleeding as well as the low iron helps stop it coming back.
How long does it take to feel better after starting iron?
Many people start to feel better within a few weeks of treatment, but it takes longer to rebuild your iron stores fully. Your doctor will usually recheck your blood to see how you're responding.
Can you have low iron without anaemia?
Yes. Your iron stores can be low before your haemoglobin drops. A ferritin blood test can show this, and some people have symptoms like tiredness at this stage.
Is it safe to take iron supplements without a test?
It's best to get tested first. A doctor needs to find out why your iron is low, and too much iron can be harmful. A pharmacist or doctor can advise you.
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This guide is general information written to help you understand your options. It is not a substitute for advice from a doctor, lawyer or financial adviser who knows your situation — if you have worrying symptoms, please see a health professional.