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Anemia occurs when the number of red blood cells circulating in the body decreases. It is the most common blood disorder.
It often develops as a result of other health issues that interfere with the body’s production of healthy red blood cells (RBCs) or increase the rates of the breakdown or loss of these cells.
In this article, we explain the types, symptoms, and causes of anemia, as well as the treatments available.
The most common symptom of anemia is fatigue. Other common symptoms include:
- pale skin
- a fast or irregular heartbeat
- shortness of breath
- chest pain
People with mild anemia may experience few or no symptoms.
Some forms of anemia cause specific telltale symptoms, including:
- Aplastic anemia: This can cause a fever, frequent infections, and skin rashes.
- Folic acid deficiency anemia: This can cause irritability, diarrhea, and a smooth tongue.
- Hemolytic anemia: This can cause jaundice, dark urine, a fever, and abdominal pain.
- Sickle cell anemia: This can cause painful swelling in the feet and hands, as well as fatigue and jaundice.
The body needs RBCs to survive. They transport hemoglobin, a complex protein that attaches to iron molecules. These molecules carry oxygen from the lungs to the rest of the body.
Various health conditions can result in low levels of RBCs.
There are many types of anemia and no single cause. In some people, it can be difficult to identify what is causing a low low RBC count.
The three main causes of anemia are:
Iron-deficiency anemia is the most common type of anemia, and blood loss is often the cause. A shortage of iron in the blood leads to this form of the condition, and low iron levels frequently occur as a result of blood loss.
When the body loses blood, it draws water from tissues beyond the bloodstream to help keep the blood vessels full. This additional water dilutes the blood, reducing the RBC count.
Blood loss can be acute and rapid or chronic. Some causes of rapid blood loss include surgery, childbirth, and trauma.
Other causes of anemia due to blood loss include:
- gastrointestinal conditions, such as ulcers, hemorrhoids, cancer, or gastritis
- the use of nonsteroidal anti-inflammatory drugs, such as aspirin and ibuprofen
- heavy menstrual bleeding
Decreased or impaired RBCs
Bone marrow is soft, spongy tissue at the center of bones, and it plays an essential role in creating RBCs. The marrow produces stem cells, which develop into RBCs, white blood cells, and platelets.
A number of diseases can affect bone marrow, including leukemia. This is a type of cancer that triggers the production of excessive and abnormal white blood cells, disrupting the production of RBCs.
Problems with bone marrow can cause anemia. Aplastic anemia, for example, occurs when few or no stem cells are present in the marrow.
In some cases, anemia results when RBCs do not grow and mature as usual, as with thalassemia — a hereditary form of anemia.
Other types of anemia that occur due to decreased or impaired RBCs include:
Sickle cell anemia
This causes RBCs to be shaped like crescents. They may break down more quickly than healthy RBCs or become lodged in small blood vessels.
This blockage can reduce oxygen levels and cause pain further down in the bloodstream.
This involves the body producing too few RBCs due to a lack of iron in the body.
Iron-deficiency anemia may develop as a result of:
- a diet low in iron
- frequent blood donation
- endurance training
- certain digestive conditions, such as Crohn’s disease
- medications that irritate the gut lining, such as ibuprofen
Vitamin B-12 and folate are both essential for the production of RBCs. If a person does not consume enough of either vitamin, their RBC count may be low.
Some examples of vitamin-deficiency anemia include megaloblastic anemia and pernicious anemia.
Destruction of RBCs
These cells typically have a life span of 120 days in the bloodstream, but the body may destroy or remove them before they complete their natural life cycle.
One type of anemia that results from the destruction of RBCs is autoimmune hemolytic anemia. It occurs when the immune system mistakes RBCs for a foreign substance and attacks them.
Many factors can cause an excessive breakdown of RBCs, including:
There is a range of treatments for anemia. Each aims to increase the number of RBCs, which, in turn, increases the amount of oxygen in the blood.
Below, we outline treatments for several types of anemia:
- Iron-deficiency anemia: Iron supplements and dietary changes can help, and, when relevant, a doctor will identify and address the cause of excessive bleeding.
- Vitamin deficiency anemia: Treatments can include dietary supplements and vitamin B-12 shots.
- Thalassemia: Treatments include folic acid supplements, iron chelation, and, for some people, blood transfusions and bone marrow transplants.
- Anemia due to chronic disease: The doctor will focus on resolving the underlying condition.
- Aplastic anemia: Treatment involves blood transfusions or bone marrow transplants.
- Sickle cell anemia: Treatment typically involves oxygen therapy, pain relief medication, and intravenous fluids, but it can also include antibiotics, folic acid supplements, blood transfusions, and a cancer drug called hydroxyurea.
- Hemolytic anemia: The treatment plan may include immunosuppressant drugs, treatments for infections, and plasmapheresis, which filters the blood.
Iron supplements are available to purchase online.
If nutritional deficiencies are responsible for anemia, eating more iron-rich foods can help.
The following foods are high in iron:
- iron-fortified cereals and breads
- leafy green vegetables, such as kale, spinach, and watercress
- pulses and beans
- brown rice
- white or red meats
- nuts and seeds
- dried fruits, including apricots, raisins, and prunes
Anemia can occur in people of all ages, sexes, and ethnicities.
The following factors increase the risk of developing a form of the condition:
- having been born prematurely
- being between 6 months and 2 years old
- being pregnant and giving birth
- having a diet low in vitamins, minerals, and iron
- regularly taking medications that inflame the stomach lining, such as ibuprofen
- having a family history of inherited anemia, such as sickle cell anemia or thalassemia
- having an intestinal disorder that affects the absorption of nutrients, such as Crohn’s disease
- losing blood, due to surgery or trauma, for example
- having a chronic illness, such as AIDS, diabetes, kidney disease, cancer, rheumatoid arthritis, heart failure, or liver disease
There are various ways to diagnose anemia, but the most common way involves a blood test called a complete blood count (CBC).
This measures a number of components, including:
- hematocrit levels, which involves comparing the volume of RBCs with the total volume of blood
- hemoglobin levels
- an RBC count
A CBC can give an indication of overall health. It can also help the doctor decide whether to check for underlying conditions, such as leukemia or kidney disease.
If RBC, hemoglobin, and hematocrit levels fall below the normal range, a person is likely to have some form of anemia.
However, it is possible for a healthy person’s levels to fall outside this range — a CBC is not conclusive, but it is a helpful starting point.
The outlook for a person with anemia depends on the cause. People can sometimes prevent or manage anemia by making dietary changes alone.
Other types of anemia are lasting, and some can be life threatening without treatment.
If a person feels continually weak and tired, they should see a doctor for testing.
Anemia occurs when a low number of RBCs are circulating in the body. This reduces the person’s oxygen levels and can lead to symptoms such as fatigue, pale skin, chest pain, and breathlessness.
There are over 400 types of anemia. Common causes are blood loss, reduced or impaired RBC production, and the destruction of RBCs.
The most common type is iron-deficiency anemia. It sometimes develops due to a diet lacking in nutrients, Crohn’s disease, or the use of certain medications.
A doctor can use a CBC blood test to help detect anemia. Treatment varies, depending on the type, but it may include iron or vitamin supplements, medications, blood transfusions, and bone marrow transplants.
However, for some people with anemia, dietary changes can resolve the issue.