Last updated on October 13, 2021.
Anemia (or anaemia) is a hematologic disorder associated with a decrease in the ability of the blood to carry enough oxygen inside the body. Symptoms of anemia are usually noticeable, such as tiredness or weakness. Depending on the causes and types of anemia, it can be a mild or severe condition which would result in different treatment regimens. Learn more about the causes, types and symptoms of anemia.
Anemia Meaning: What is Anemia?
Hemoglobin (Hb) is a protein in the red blood cells responsible to carry oxygen from the lungs to all parts of the body. When people get anemia, it is usually defined as a low hemoglobin concentration due either to a decrease in the total number of red blood cells or a decrease in the concentration of hemoglobin. In such a way, anemic patients cannot obtain adequate oxygen to support normal metabolism, meaning that the cells are not able to get enough energy for survival. Therefore, common symptoms of anemia are usually fatigue, dizziness, dyspnoea, etc.
Causes and Types of Anemia
Causes of anemia are related to the production, destruction and function of red blood cells or hemoglobin. Certain nutrients are essential to make new red blood cells or hemoglobin, and the lack of them is the most common cause of anemia.
- Iron-deficiency anemia: This is the most common type of anemia, which is due to insufficient iron in the body to produce new hemoglobin. It can be caused by blood loss, such as heavy menstrual bleeding or gastrointestinal bleeding, poor diet and pregnancy.
- Anemia of chronic disease (secondary anemia): This is the second most common type of anemia in the world, prevalent in hospitalized patients. It can be caused by many conditions such as chronic infection, rheumatoid, and malignancy which would greatly influence the production of red blood cells.
- Folate-deficiency anemia: Folate (or called folic acid) is responsible for making both DNA and red blood cells. It is usually found in green vegetables and nuts. Poor diet, some medications (e.g. Methotrexate, Phenytoin), and pregnancy may give rise to this type of anemia.
- Vitamin B12-deficiency anemia: The function of vitamin B12 is similar to that of folate. It is usually found in meat and fish but not in most plants. This type of anemia is commonly caused by dietary, gastrectomy, and some autoimmune diseases (e.g. Crohn’s disease).
- Pernicious anemia: It is an autoimmune condition due to the inability of the stomach to produce intrinsic factor (IF), which is a protein needed for vitamin B12 absorption.
- Aplastic anemia: This is a rare stem cell disorder in which bone marrow stops making cells, including red blood cells, white blood cells and platelets. Most causes are irradiation, autoimmune and toxic drugs.
- Hemolytic anemia: Hemolysis is the premature breakdown of red blood cells, before their normal lifespan of around 120 days. Hemolysis may be asymptomatic, but if the bone marrow does not compensate for the breakdown sufficiently, hemolytic anemia would result. It can be acquired (e.g. drug-induced, autoimmune) or hereditary (e.g. Sickle-cell disease, Thalassemia).
- Sideroblastic anemia: This is a bone marrow disorder in which the body has enough iron but is unable to make enough hemoglobin. It can be acquired, hereditary or idiopathic.
Signs and Symptoms of Anemia
Due to the underlying cause or to the anemia itself, the following signs and symptoms of anemia may occur:
- Lack of energy
- Shortness of breath
- Palpitation: Sensation of sudden heartbeats changing which are more noticeable than usual. Palpitation usually occurs along with arrhythmia, appearing as irregular pounding and fluttering heartbeats.
- Loss of appetite
Diagnosis of Anemia
In addition to the signs and symptoms, anemia is mainly diagnosed by blood tests.
- Complete blood counts (CBC): The simplest way to confirm anemia is to check the number of red blood cells and hemoglobin in circulation. Anemia is indicated when these levels are below normal.
- Peripheral blood smear: it is an examination of a peripheral blood sample under a microscope to observe any abnormality of shape, color, and size of the red blood cells.
- Physical examination for internal bleeding: Physicians may carry out any physical examinations to look for signs of internal bleeding or any other causes of anemia. Common examples including fecal occult blood test (FOBT), upper gastrointestinal endoscopy, and colonoscopy are sometimes applied if gastrointestinal bleeding is suspected.
Risk Factors of Anemia
Anemia can be acquired, hereditary, or idiopathic (unknown causes), however these groups of people may have a higher risk of developing anemia:
- Pregnancy: Blood volume is increased to support the growth of the fetus during pregnancy, it would also increase the supply of nutrients for making red blood cells and hemoglobin. Therefore, when your body demands more iron than is available (e.g. lack of diet), anemia may develop.
- Dietary: Heavy drinking and a poor diet with low iron, folate and vitamin B12 are very likely to develop anemia. Therefore, it is important to have a healthy and balanced diet.
- Family history: The risk of anemia increases when your family members have a history of inherited anemia, such as sickle-cell disease and thalassemia.
- Intestinal diseases: Crohn’s disease and celiac disease can affect iron absorption, thus increasing the risk of anemia.
- Premenopausal women: Loss of red blood cells can be caused by menstruation so premenopausal women are more likely to develop anemia than men and postmenopausal women.
- Age: People aged 65 years or above have a higher risk of anemia.
- Other conditions: Medications (e.g. anticonvulsants, chemotherapy), autoimmune diseases, infections, etc. may contribute to anemia development as well.
Complications of Anemia
Although some types of anemia are mild and temporary, severe and fatal complications may occur if it is undiagnosed or left untreated, for instance:
- Pregnancy complications: Preterm delivery or delivering a baby with low birth weight can happen in pregnant women.
- Heart problems: Since your blood does not carry enough oxygen, your heart would work harder and pump more blood to compensate for the lack of oxygen. This may result in irregular heartbeat, enlarged heart or even heart failure.
- Lasting and severe fatigue: It can greatly diminish your productivity in daily activities.
- Weaken immune system: Anemia can affect your immune system, so you may be more susceptible to infections.
Treatments of Anemia
Treatment of anemia, which can range from dietary supplements to surgery, depends mainly on the cause and severity. In general, anemia can be treated by the following approaches:
- Supplementations: Over-the-counter Iron (e.g. Iron polymaltose and Ferrous sulfate), folic acid and vitamin B12 supplements are usually the most direct way to treat nutritional anemia, if the conditions are not caused by bleeding or malabsorption. Also, vitamin C supplementation may be used to promote iron absorption.
- Lifestyle modification: In addition to supplementation, a healthy eating pattern is also helpful to obtain more nutrients. Iron-rich foods include dried fruit, beans and red meats. Foods rich in vitamin C include oranges, strawberries and tomatoes. Vitamin B12 can be found in meat and fish, whereas folic acid is usually found in green vegetables and nuts.
- Blood transfusion: In more acute and severe conditions where patients need an immediate increase in blood volume, blood transfusion may be indicated.
- Medications: Erythropoiesis-stimulating agents (ESA), such as Darbepoetin alfa and Epoetin alfa, can be used to treat anemia associated with chronic kidney disease, chemotherapy or HIV-therapy. They stimulate the bone marrow to make more red blood cells (erythropoiesis) and are given as an intravenous injection. On the other hand, intravenous iron therapy is also considered when the patient has chronic conditions such as kidney disease or celiac disease.
- Surgery: In terms of internal bleeding, anemia can be corrected by surgery if it is mainly associated with blood loss.
- Treating the underlying causes: Other causes, such as heavy bleeding or infection, should be identified and addressed.
- Stem cell transplantation and Immunosuppressants: These treatments, based on the severity of the condition and the age, are available for aplastic anemia.
Prevention of Anemia
Many types of anemia cannot be prevented, except for nutritional anemia related to iron, folate and vitamin B12 deficiency. A balanced diet is essential to avoid such types of anemia.
- Foods rich in iron and vitamin C: Diet rich in iron and vitamin C can lower the risk of iron-deficiency anemia. Foods like dried fruit, beans, red meats, oranges, strawberries and tomatoes are good sources.
- Foods rich in folate: Folate is naturally present in many foods, such as dark green leafy vegetables, fruits, nuts, beans, seafood and eggs.
- Foods rich in vitamin B12: Vitamin B12 can be found in animal liver, clams, salmon, beef and tuna.
- Multivitamins: If you are worried about being unable to get enough nutrients from the above foods, consult your doctor, pharmacist, dietitian or nutritionist to see whether you need multivitamins or not.
The most common cause of anemia is inadequate iron storage in the body, causing iron-deficiency anemia. Iron is essential for making hemoglobin, which is a protein to carry oxygen throughout your body for metabolism. Anemia can be temporary or chronic, depending on its type and severity. Since the most common type of anemia is due to iron deficiency, the fastest way to cure such anemia is to consume more iron and vitamins via supplementation and diet (e.g. dried fruit, beans, red meats, oranges, strawberries, tomato). Symptoms of anemia are quite obvious and noticeable. Common ones are fatigue (tiredness), lack of energy, faintness, and headache. Less common symptoms of anemia include palpitation, shortness of breath, tinnitus, and loss of appetite. Anemia caused by iron deficiency can be treated with iron-rich and vitamin C-rich foods and drinks. Drinks that are high in iron include spinach juice, pumpkin juice and beetroot juice. Vitamin C-rich drinks are also beneficial to anemia prevention such as citrus juice, tomato juice and strawberry juice.
What is the main cause of anemia?
What is the fastest way to cure anemia?
What are the symptoms of anemia?
What drink is high in iron?
The most common cause of anemia is inadequate iron storage in the body, causing iron-deficiency anemia. Iron is essential for making hemoglobin, which is a protein to carry oxygen throughout your body for metabolism.
Anemia can be temporary or chronic, depending on its type and severity. Since the most common type of anemia is due to iron deficiency, the fastest way to cure such anemia is to consume more iron and vitamins via supplementation and diet (e.g. dried fruit, beans, red meats, oranges, strawberries, tomato).
Symptoms of anemia are quite obvious and noticeable. Common ones are fatigue (tiredness), lack of energy, faintness, and headache. Less common symptoms of anemia include palpitation, shortness of breath, tinnitus, and loss of appetite.
Anemia caused by iron deficiency can be treated with iron-rich and vitamin C-rich foods and drinks. Drinks that are high in iron include spinach juice, pumpkin juice and beetroot juice. Vitamin C-rich drinks are also beneficial to anemia prevention such as citrus juice, tomato juice and strawberry juice.
*This article was medically reviewed by Dr. Gordon Chak Man Cheung from the London Medical Clinic, Central, Hong Kong. Dr. Cheung is a General Practitioner in HK who received his medical degree from King’s College London, University of London. Before completing his General Practice specialist training in UK, Dr. Cheung had worked in various hospitals in London and South East England in Cardiology, Endocrinology, Oncology, Paediatrics, Obstetrics and Gynaecology. He holds numerous postgraduate medical qualifications including Memberships to the Royal Colleges of Physicians in UK and to the Royal College of General Practitioners, Diploma of the Royal College of Obstetricians and Gynaecologists, Child Health as well as Clinical Dermatology.