What is anemia?

By Dr Ananya Mandal, MD

Anemia is due to lack of haemoglobin in the blood which is below the normal level or due to less than normal levels of red blood cells in blood.

The haemoglobin helps carry oxygen in blood. Lack of haemoglobin thus causes deficiency of life giving oxygen to vital organs. (1-4)

Types of anemia

There are various causes of anemia. It could be due to:

  • Decreased production of RBCs in blood
  • Increased blood loss OR
  • Excessive destruction of RBCs

Causes of anemia

Anemia most commonly occurs due to nutritional problems. This includes lack of iron in the diet.

Iron deficiency is the commonest form of anemia.

In the United States 7% of toddlers ages 1 to 2 years old and 9-16% of menstruating women suffer from iron deficiency.

The poorer nations 30-70% of the people have iron deficiency anemia.

Iron and anemia

Since iron is needed for the manufacture of haemoglobin in the body its deficiency can lead to anemia.

Iron is found in meat, dried fruit and some vegetables.

Lack of iron may be caused due to bleeding especially in stomach ulcers or within the intestines.

Women before menopause commonly suffer from iron deficiency anemia due to heavy periods and increased demands during pregnancy.

Vitamins and anemia

Certain vitamins like vitamin B12 and folic acid or folate are also essential in the normal production of RBCs in blood. Their lack in diet may lead to anemia.

Both vitamin B12 deficiency and folate deficiency are more common in older people, affecting around 1 in 10 people above the age of 75.

There is an inherited condition called Pernicious anemia where patients find it difficult to use the vitamin B 12 in diet for production of healthy RBCs. This is a rare condition and affects 1 in 10,000 people in northern Europe.

Other causes of anemia

Increased blood loss due to surgery or major trauma may lead to anemia.

Excessive destruction of RBCs may occur due to certain conditions called haemolytic anemias. These are often inherited and include Sickle cell anemia, Thalassemia etc. Anemia can also occur in severe infections, cancers and due to exposure to a drug or toxin.

For example, the RBCs are made in bone marrow. If there is cancer in the marrows a shortage of good red blood cells results. This is called aplastic anaemia and may also occur with blood cancers like leukaemia.

Symptoms of anemia

People with mild anemia may not have any symptoms or may have only mild symptoms.

People with severe anemia may have more severe symptoms that may be life-threatening.

The commonest symptoms of anemia, particularly iron deficiency anemia, are lack of energy and fatigue. Severe anemia may lead to shortness of breath, pale complexion, dry nails, palpitations etc.

Children with anaemia, like adults, may appear pale, tired and short of breath. They may give in to eating inappropriate non-food material like mud, chalk etc. This is called pica.

Anemia in children may lead to behavioural and intellectual development problems.

If not managed severe anemia can lead to several complications. Anemia reduced immunity and can leave a patient susceptible to illness and infection.

Severe cases may lead to palpitations and even heart failure. This failure occurs if the heart is not pumping blood around the body efficiently.

Pregnant women have an additional risk of complications before and after birth.

Treatment of anemia

Treatment depends on the cause of the anaemia. If the anaemia is due to a lack of iron, eating iron-rich food or iron supplements may be given.

If, however, the cause of anemia is deeper like internal bleeding or cancers, the cause should be explored before treatment.

When the anaemia is more severe, a blood transfusion may be prescribed.

Edited by , BA Hons (Cantab)

Further Reading

Anemia Causes
Anemia Symptoms
Anemia Diagnosis
Anemia Treatments

Last Updated: Jul 4, 2012

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