| 14.8°C Dublin

Anaemia is the most common blood disorder for patients


Blood loss is the most common cause of anaemia.

Blood loss is the most common cause of anaemia.

Getty Images/Science Photo Library RF

Dr Nina Byrnes

Dr Nina Byrnes


Blood loss is the most common cause of anaemia.

Question: I have been feeling quite tired lately. I went to my doctor and my blood tests show that I have anaemia. I consider myself quite healthy and I eat well so I'm not sure how this occurred. Is there anything else I should have checked and how can I prevent this in the future?

Answer: Blood is made up of three main types of cells. White cells help the body fight infection. Platelets help stop bleeding in the body and red blood cells carry oxygen and nutrients around the body.

Red blood cells contain haemoglobin - this is an iron-rich protein that gives blood its red colour. It attaches to oxygen in the lungs and carries it around the body. Anaemia occurs when there aren't enough red blood cells or if there is a lack of haemoglobin in these cells.

There are three main causes of anaemia. These are: blood loss, a lack of production of red blood cells, or excess destruction of red blood cells. Some types of anaemia are short lived and have few symptoms, others may be long lasting. Severe anaemia can increase the risk of death.

Blood loss is the most common cause of anaemia. This may be normal such as that which occurs in menstruation or it may be due to injury or surgery. Bleeding in the gut can also cause this anaemia. Anaemia due to blood loss is usually associated with low levels of iron.

There are a number of factors that may lead to reduced red blood cell production. A diet low in vitamin B12, folic acid or iron may increase the risk of this. Other vitamins such as vitamin C, riboflavin and copper are also important in red blood cell production. Conditions such as coeliac disease, inflammatory bowel conditions and surgery to the stomach may reduce the absorption of nutrients and alter red cell production levels. Chronic illness such as kidney disease and cancer can also affect the body's ability to produce red blood cells.

In sickle-cell disease red blood cells produced are an abnormal shape and have a short lifespan dying off after 10 to 20 days rather than 120 days. The bone marrow which produces blood cells can't keep up with demand and so anaemia can occur.

In thalassemia the proteins that make up haemoglobin are either missing or defective, meaning the body can make fewer red blood cells and less haemoglobin, resulting in anaemia. Sickle cell disease and thalassemia are inherited conditions that are more common in those of Mediterranean, Middle Eastern or African descent.

Haemolytic anaemia results in the destruction of too many red blood cells. This type of anaemia can be inherited or can be due to infections, autoimmune conditions, a reaction to medication or after blood transfusion.

Anaemia is the most common blood disorder and can occur in all ages and races. Women of childbearing years are particularly at risk due to blood loss from menstruation and childbirth. Pregnancy also poses an increased risk as the body produces more fluid than red blood cells during this time, effectively diluting the blood.

Babies and toddlers are also particularly at risk. Cow's milk is low in iron so those who drink lots of milk may be deficient. Consuming calcium-rich foods with iron can also reduce the absorption of iron from the gut so adults who take milk with meals may be at risk.

If anaemia is mild you may have no symptoms at all. Feeling tired or lacking in energy are the most common symptoms of anaemia. Other symptoms include dizziness, ringing or whooshing in your ears, headaches, cold hands and feet, pale skin, a fast heartbeat, or chest pain. In severe anaemia the heart may suffer and abnormal heart rhythms or even heart failure can occur. Most of the symptoms are due to a lack of oxygen in the blood.

Anaemia is usually diagnosed with a simple blood test. A full blood count will check your haemoglobin levels but your doctor will also likely check your levels of iron, vitamin B12 and folic acid to try and narrow down the cause.

If you are menopausal, have any digestive symptoms or are over 50 you may be referred for a gastroscopy and colonoscopy to rule out any blood loss from your gut. If a more unusual cause is suspected you may be advised to have bloods to check for autoimmune conditions or genetic disorders such as sickle-cell disease. In rare cases the opinion of a blood specialist (haematologist) may be sought.

If you are diagnosed with anaemia the cause should be identified and treated. If iron levels are low, taking a supplement can help. If haemoglobin levels are very low blood transfusion is sometimes required. Foods rich in iron include red meat, dark green leafy vegetables such as spinach, pulses, lentils and beans, dried fruits and fortified cereals. When consuming iron-rich foods try and include other foods high in vitamin C, especially citrus fruits, as this aids the absorption of iron from the digestive tract. Foods rich in calcium will reduce absorption so should be taken separately.

Eating a healthy diet and leading a healthy lifestyle is the best way to prevent anaemia. Processed foods tend to be calorie-rich and nutrient-deficient and should be avoided.

Health & Living