Anaemia and low iron: symptoms, causes, tests and iron-rich diet

Feeling tired all the time can have many causes, and anaemia is one possible cause. This article explains what anaemia is, why low iron can cause it, how it is found and managed, and when to see a doctor, using information from the World Health Organization (WHO), the NHS and MedlinePlus.

1. Introduction

Anaemia is a condition in which the body has fewer red blood cells, or less haemoglobin inside them, than normal. Haemoglobin is the protein that carries oxygen, so less of it means organs and tissues get less oxygen. WHO describes anaemia as a sign of an underlying problem and says it is preventable and treatable ^[2].

MedlinePlus says the most common cause is not having enough iron, because the body needs iron to make haemoglobin ^[3]. Iron deficiency anaemia is the most common type, according to the NHS ^[1]. WHO estimates that about 30% of women aged 15 to 49, 37% of pregnant women and 40% of children aged 6 to 59 months are affected worldwide ^[2]. WHO says anaemia can lower school performance and productivity in adult life ^[2].

2. Signs and symptoms

The NHS lists these common symptoms of iron deficiency anaemia ^[1]:

• Tiredness and low energy
• Shortness of breath
• Heart palpitations, which means feeling your heartbeat
• Paler skin than usual
• Headaches

Less common signs include ringing in the ears, altered taste, itchy skin, a sore tongue, hair loss, difficulty swallowing, spoon-shaped nails, restless legs and pica, which is a craving for non-food items such as ice or paper ^[1]. WHO adds dizziness, cold hands and feet and breathlessness on exertion, and says severe anaemia can cause fast breathing and heart rate and easy bruising ^[2].

3. Causes and risk factors

According to the NHS, heavy periods and pregnancy are very common causes. Bleeding from the digestive system is another, and can come from stomach ulcers, piles or inflammation of the bowel or gullet. Anti-inflammatory pain relievers such as ibuprofen and aspirin can contribute to this bleeding, and less commonly it is caused by bowel or stomach cancer ^[1].

WHO describes further causes ^[2]:

• Too little iron in the diet, and shortages of folate, vitamin B12 or vitamin A
• Infections such as malaria, tuberculosis, HIV and hookworm
• Long-term illnesses that cause inflammation
• Inherited blood disorders such as thalassaemia and sickle cell disorders

MedlinePlus says anaemia has three main causes: blood loss, making too few red blood cells, and red blood cells being destroyed too quickly. It also lists vitamin B12 deficiency anaemia and anaemia of inflammation or chronic disease among the types ^[3].

4. Diagnosis and tests

A doctor asks about your health and lifestyle and usually orders a full blood count, a simple blood test that measures red blood cells and other blood cells. No special preparation is needed. If the cause is unclear, the NHS says the doctor may arrange a stool test for hidden blood or refer you to a specialist ^[1]. MedlinePlus links to a range of blood tests, including iron tests, a ferritin test and vitamin B tests, and says treatment depends on the type of anaemia ^[3].

5. Treatment and diet

Treatment depends on the cause ^{[2, 3]}. The NHS explains that the cause itself, such as an ulcer or heavy periods, may need treatment. Iron tablets prescribed by a doctor are usually taken for about 6 months, and repeat blood tests check recovery. Taking tablets with food can reduce side effects such as constipation or stomach upset, and the tablets can be dangerous for young children, so keep them out of reach ^[1].

Food choices help absorption. The NHS suggests more dark green leafy vegetables, pulses such as beans and lentils, meat, dried fruit and fortified cereals. Large amounts of tea, coffee and dairy, and foods high in phytic acid such as wholegrains, can reduce iron absorption ^[1]. WHO adds that vitamin C taken with iron-rich foods boosts absorption, and that calcium and iron supplements should be taken at different times of day. It advises taking supplements only if a health professional recommends them ^[2].

6. Prevention and special groups

WHO says prevention includes a varied diet with iron-rich foods, treating heavy menstrual bleeding, preventing and treating malaria and worm infections where relevant, and spacing pregnancies at least 24 months apart ^[2].

Young children, menstruating adolescent girls and women, and pregnant and postpartum women are most affected. WHO links anaemia in pregnancy with premature birth, low birth weight and maternal death, and says severe anaemia in children can affect development and school performance ^[2]. WHO also reports that low and lower-middle-income countries, rural residents, poorer households and people with no formal education carry a heavier burden ^[2]. Untreated iron deficiency can also raise the risk of infections and strain the heart ^[1].

7. When to see a doctor

The NHS advises a non-urgent appointment if you think you may have iron deficiency anaemia ^[1]. WHO advises people with heavy menstrual bleeding to see a doctor, and to consult a health-care provider early if symptoms appear ^[2]. The NHS lists breathlessness and palpitations among the symptoms and says untreated iron deficiency can strain the heart and lungs ^[1]. WHO also names pregnancy and blood loss around childbirth as causes, so pregnant women with symptoms should speak to their health-care provider ^[2].

In an emergency, call your local emergency number (112 in India, 911 in the United States).

8. Conclusion

Anaemia is common, often caused by low iron, and is preventable and treatable. A simple blood test can find it, and the cause must be identified so that the right treatment is chosen. Iron-rich food, good absorption habits and prompt review of heavy bleeding all help, and your doctor decides on any supplement.