All you need to know about anaemia, including the most common symptoms, what causes this blood disorder, those most at risk, and the different types of anaemia that exist.

7 minute read

Anaemia (spelt anemia in the United States) is a blood disorder where you don’t have enough red blood cells in your body. Red blood cells carry oxygen around your body to your tissues and organs.

There are several different types of anaemia, but the most common type is iron deficiency anaemia. An estimated 3% of men and 8% of women in the UK have iron deficiency anaemia.

This article will focus on iron deficiency anaemia, with a brief look at other, less common forms of the condition.

What is anaemia?

The term anaemia means literally “without blood”. Specifically, iron deficiency anaemia develops when the levels of iron in your body get too low to make healthy red blood cells.

Red blood cells transport oxygen around the body in proteins called haemoglobin. In order to make healthy red blood cells, the body needs sufficient amounts of nutrients such as iron and vitamin B12. If your body doesn’t have enough of these nutrients, your haemoglobin level will decrease, and iron deficiency anaemia can result.

Iron deficiency anaemia reduces your body’s ability to supply your organs with oxygen, meaning your body has to work harder to compensate by increasing your breathing and heart rate.

Anaemia symptoms

Anaemia symptoms often develop gradually and may be overlooked or put down to other factors, like tiredness or stress. Symptoms vary from person to person and can be mild or severe.

Common symptoms of anaemia include:

• Pale skin

• Inside the lower eyelid may be pale pink or yellow instead of bright red

• Fatigue

• Getting tired easily

• Shortness of breath

• Palpitations  

Less common symptoms of anaemia include:

• Feeling dizzy or lightheaded when standing from a sitting or lying position (orthostatic hypotension)

• Frequent headaches

• Irritability

• Difficulty concentrating

• Tinnitus

• Itching

• Sore, cracked, or reddened tongue

• Hair loss

• Food tasting strange

• Spoon-shaped nails (koilonychia)

• Strange food cravings, or a desire to eat non-food items, such as paper or ice (pica)

• Difficulty swallowing (dysphagia)

• Sores at the corners of your mouth

• Restless legs syndrome

• Loss of appetite

What causes anaemia?

There are several different types of anaemia with various causes. Iron deficiency anaemia is commonly caused by a lack of iron in the diet, pregnancy, or blood loss.

Causes of anaemia include:

• Diet - lack of iron, vitamin B12 or folic acid in the diet.

• Blood loss - may be acute and severe as a result of trauma or surgery, or slow and chronic due to conditions such as heavy menstrual periods, gastric ulcers, or colorectal polyps.

• Pregnancy - iron deficiency anaemia is common during pregnancy as your blood volume increases, but the amount of red blood cells stays the same.

• Malabsorption - anaemia can result from problems absorbing nutrients from food due to conditions such as coeliac disease.

• Autoimmune disorders  - some autoimmune disorders such as autoimmune haemolytic anaemia or thyroid disease can decrease the life span of red blood cells.

• Inherited disorders such as thalassaemia, sickle cell disease or porphyria.

• Chronic inflammatory diseases such as arthritis can reduce the body’s ability to utilise iron.

• Kidney disease - the kidneys produce a hormone called erythropoietin (EPO) that tells your body to make red blood cells. In kidney disease, the kidneys do not produce enough EPO, resulting in less red blood cells being produced.

• Bone marrow disorders such as blood cancer cause a decrease in the production of red blood cells.

• Medications or toxins - Some toxins and medications can damage bone marrow or reduce bone marrow function.

• Infections - some infections like malaria can trigger mechanisms that may lead to iron deficiency anaemia.

Who is at risk of developing anaemia?

Anaemia is particularly common among young children, menstruating females, pregnant women, and women who have recently given birth.

According to the World Health Organisation (WHO) an estimated 40% of children between six and 59 months of age, 37% of pregnant women, and 30% of women aged 15 to 49 years of age have iron deficiency anaemia worldwide.

Other risk factors for developing anaemia include:

• Being on a restrictive diet such as vegetarian or vegan

• Certain medical conditions, including cancer, stomach ulcers, uterine fibroids, some autoimmune diseases, and some chronic diseases like kidney disease

• Age - anaemia is more common in people over the age of 65

Types of anaemia

There are several types of anaemia, but they all result in a reduction in the number of red blood cells.

Nutritional anaemias

• Iron-deficiency anaemia - this is the most common type of anaemia. It occurs when your body doesn’t have enough iron to produce haemoglobin, the substance that enables your red blood cells to carry oxygen throughout your body.

• Pernicious anaemia - this is an autoimmune condition that prevents your body from absorbing vitamin B12.

• Megaloblastic anaemia - this rare type of anaemia is usually caused by a deficiency of vitamin B12 and/or vitamin B9 (folate).

Anaemias caused by abnormal red blood cells

• Haemolytic anaemia - this type of anaemia causes your red blood cells to break down or die faster than your body can replace them. It can be caused by an inherited condition, infection, some medications, or a blood transfusion from a mismatched donor. Haemolytic anaemia can be inherited (passed down from your parents) or acquired (develops later in life).

• Autoimmune haemolytic anaemia - this rare type of anaemia occurs when your immune system mistakenly attacks your red blood cells.

• Sideroblastic anaemia - in this type of anaemia, your body is unable to use iron to make red blood cells. This causes a buildup of iron in the body and a decrease in red blood cells.

• Aplastic anaemia - a rare, but serious type of anaemia that happens when your bone marrow doesn’t make enough new blood cells and platelets.

• Macrocytic anaemia - this rare form of anaemia happens when your bone marrow makes abnormal, unusually large red blood cells that do not function properly.

• Microcytic anaemia - this type of anaemia occurs due to a lack of haemoglobin and causes low levels of red blood cells that are smaller than usual.

• Normocytic anaemia - usually accompanies another health condition such as cancer, kidney disease or rheumatoid arthritis. With normocytic anaemia, you have fewer red blood cells than usual that don’t contain enough haemoglobin.

Inherited anaemias

• Sickle cell anaemia - sickle cell anaemia changes the shape of your red blood cells, causing them to become stiff and sticky and block blood flow.

• Diamond-Blackfan anaemia - in this rare inherited disorder, the bone marrow malfunctions and doesn’t make enough red blood cells.

• Fanconi anaemia - this is a rare genetic disorder that has multiple effects on the body. One effect is that the bone marrow cannot produce enough of all types of blood cells (aplastic anaemia)

When should I see a doctor?

See your GP if you have symptoms of anaemia such as fatigue, weakness, pale skin, palpitations, and shortness of breath.

How is anaemia diagnosed?

Anaemia is easily diagnosed with a blood test called a full blood count (FBC). Your GP may ask you some questions about your general health and lifestyle to determine the cause of your anaemia.

If a clear cause cannot be found, your GP may perform a physical examination, or refer you to a specialist.

How is anaemia treated?

So, how do you treat anaemia?

Treatment for anaemia depends on the type of anaemia and the underlying cause. Iron deficiency anaemia is normally treated with changes to your diet or, in some cases, iron tablets.

If your anaemia is caused by chronic blood loss, your GP will also treat the underlying cause. In some cases, your GP may refer you to a specialist for treatment.

Can anaemia be prevented?

It isn’t possible to prevent some types of anaemia such as inherited anaemia, or anaemias caused by chronic disease.

You can help prevent anaemia caused by dietary deficiencies by eating a range of foods, including dairy, fresh fruits, vegetables, lean meats, nuts, and legumes.

If you follow a vegan or vegetarian diet, talk to your healthcare provider about taking a recommended vitamin and mineral supplement.

Conclusion

Anaemia refers to a range of conditions where there are lower than normal levels of oxygen-carrying red blood cells in the body, resulting in symptoms such as pale skin, shortness of breath and fatigue.

The most common type of anaemia is iron deficiency anaemia, which is commonly caused by lack of iron in the diet, blood loss or pregnancy. Sometimes, however, anaemia can develop due to an underlying health condition. Anaemia can be diagnosed with a simple blood test and is usually easily treated with changes to your diet or supplements. If you have symptoms of anaemia, be sure to make an appointment with your GP.