Anemia

What is it?

According to the NHLBI: anaemia develops when the body makes fewer healthy red blood cells than normal, so the organs do not get enough oxygen-rich blood. Its types include iron-deficiency anaemia, vitamin B12 deficiency anaemia, haemolytic anaemia and aplastic anaemia.

WHO figures for 2019: 30% of non-pregnant women aged 15 to 49 (539 million women), 37% of pregnant women (32 million) and 40% of children aged 6 to 59 months (269 million children). Anaemia accounted for the loss of about 50 million years of healthy life due to disability in 2019. In the United States, about 3 million people are affected, according to CDC data quoted in the NHLBI.

Causes

According to the WHO: iron deficiency is the most common nutritional cause; other causes include malaria, thalassaemia and sickle cell trait, deficiency of vitamin A, folate, B12 and riboflavin, infections (tuberculosis, HIV and parasites), heavy periods and bleeding after childbirth, and inherited red blood cell disorders.

According to the NHLBI: any condition in which a large amount of blood is lost raises the risk (heavy periods, gastrointestinal bleeding, surgery, injury, frequent blood donation); low iron, B12 and folate reduce production; and chronic kidney disease, infection, cancer and autoimmune diseases reduce the red cells the body produces. The NHS also mentions gastrointestinal bleeding due to non-steroidal anti-inflammatory drugs, ulcers, haemorrhoids or tumours.

Risk factors

Higher-risk groups according to the NHLBI: women during periods and pregnancy, people who do not get enough iron or vitamins, people who take certain medicines or treatments, and people with bleeding, infection, kidney disease, cancer or autoimmune disease.

Symptoms

According to the NHLBI: tiredness or weakness, shortness of breath, dizziness, headache, irregular heartbeat. According to the NHS in iron deficiency: tiredness and lack of energy, shortness of breath, noticeable palpitations, pale skin, headache; less commonly: tinnitus, altered taste, itching, a sore tongue, hair loss, craving non-food substances, difficulty swallowing, mouth ulcers, spoon-shaped nails and restless legs syndrome.

How is it diagnosed?

Diagnosis relies on medical history, physical examination and test results (NHLBI). The most important is the complete blood count (CBC), which measures red blood cells, haemoglobin, haematocrit and MCV.

Additional tests depending on the case: upper and lower gastrointestinal endoscopy to detect internal bleeding, genetic tests for changes in blood cell production, urine tests to assess the kidneys and urinary bleeding, and bone marrow aspiration and biopsy to assess its health and blood production (NHLBI). The NHS mentions the faecal immunochemical test when the cause is unclear.

• Complete blood count (CBC)Lab test
• Ferritin testLab test

Treatment

The treatment categories usually used are listed here; this is not a prescription. The doctor chooses the plan according to each person's condition; do not change any medicine or dose without a specialist.

Treatment depends on the cause and severity (NHLBI): iron supplements for iron deficiency, vitamin B12 as supplements or injections for its deficiency, immunosuppressant medicines when the cause is autoimmune, blood transfusion to raise red cells quickly in severe cases, stem cell or bone marrow transplant to replace defective cells, and surgery to treat a cause of internal bleeding.

In iron deficiency, the NHS states that tablets are usually prescribed for about 6 months, that orange juice afterwards may help absorption, and that their side effects are constipation, diarrhoea or nausea, which may ease when taken with food. It warns to keep iron tablets away from children. Do not take iron supplements without a diagnosis, because the cause (such as bleeding) needs treatment.

Prevention

According to the WHO: foods rich in iron (meat, legumes, fortified grains, leafy vegetables) together with foods rich in vitamin C to boost absorption, iron and vitamin supplements when recommended, prevention of malaria and infections, delaying cord clamping for a minute or more at birth, and treatment of inherited disorders and chronic diseases. The NHS advises limiting tea, coffee and dairy products around iron-rich meals because they hinder its absorption.

Common questions