Anemia currently affects more than 3 million Americans and an estimated 1.62 billion people, globally. Anemia is not strictly a disease, but a disorder.
It is often a byproduct of other diseases that either interfere with the body's ability to produce healthy red blood cells or abnormally increase red blood cell breakdown or loss.
In this article, we will look at the causes, symptoms, and treatments of anemia.
Here are some key points about anemia. More detail and supporting information is in the main article.
- Anemia affects an estimated 24.8 percent of the world's population
- Pre-school children have the highest risk, with an estimated 47 percent developing anemia, globally
- More than 400 types of Anemia have been identified
- Anemia is not restricted to humans and can affect cats and dogs
What is anemia?
There are many potential causes of anemia.
Anemia is diagnosed as any condition in which there is a decreased number of circulating red blood cells. Conditions where our body does not produce enough healthy red blood cells, destroys too many red blood cells, or loses circulating red blood cells can all lead to anemia.
Red blood cells are critical to our body's well-being. They carry hemoglobin, a complex protein that contains iron molecules.
The main function of these molecules is to carry oxygen from the lungs to the rest of the body.
If there are not enough red blood cells, an individual may experience symptoms such as feeling tired or weak.
There are more than 400 types of Anemia currently known, and these are divided into three main groups according to their cause:
- Anemia caused by blood loss
- Anemia caused by decreased production or production of faulty red blood cells
- Anemia caused by the destruction of red blood cells
Causes of anemia
There is no single cause of anemia. Due to the great number of anemia types, it can sometimes be difficult to pinpoint the exact cause.
Below is a general overview of the common causes of the three main groups of anemia:
1) Anemia caused by blood loss
The most common type of anemia - iron deficiency anemia - often falls into this category. In this case, the disorder is brought on by a shortage of iron, most often caused by blood loss.
When blood is lost, the body reacts by pulling in water from tissues outside the bloodstream in an attempt to keep the blood vessels filled. This additional water dilutes the blood, and, as a result, the red blood cells are diluted.
Blood loss can be categorized as acute and rapid or chronic. Rapid blood loss can include surgery, childbirth, trauma, or a ruptured blood vessel.
Causes of anemia due to blood loss include:
- Gastrointestinal conditions - such as ulcers, hemorrhoids, cancer, or gastritis
- Use of non-steroidal anti-inflammatory drugs (NSAIDs) - such as aspirin and ibuprofen
- Menstrual bleeding
2) Anemia caused by decreased or faulty red blood cell productions
Located in the center of our bones is a soft, spongy tissue, called bone marrow, it is essential for the creation of red blood cells. Bone marrow produces stem cells, which develop into red blood cells, white blood cells, and platelets.
Bone marrow can be affected by a number of diseases, including leukemia, where abnormal white blood cells are produced in excess, which disrupts normal production of red blood cells.
Other examples of anemias caused by decreased or faulty red blood cells are:
- Sickle cell anemia - red blood cells are misshapen and break down abnormally quickly. The crescent-shaped blood cells can also get stuck in smaller blood vessels, causing pain.
- Iron-deficiency anemia - not enough red blood cells are produced because not enough iron is present in the body. This can be because of a poor diet, menstruation, frequent blood donation, endurance training, certain digestive conditions, such as Crohn's disease, surgical removal of part of the gut, and some foods.
- Bone marrow and stem cell problems - for instance, aplastic anemia occurs when there are little or no stem cells present. Thalassemia occurs when red blood cells can't grow and mature properly.
- Vitamin deficiency anemia - vitamin B-12 and folate are both essential for the production of red blood cells; therefore, if either is deficient, red blood cell production will be too low. Examples of this type of anemia are megaloblastic anemia and pernicious anemia.
3) Anemia caused by the destruction of red blood cells
Red blood cells typically have a life span of 120 days in the bloodstream, but they can be destroyed or removed beforehand.
One type of anemia that falls into this category is autoimmune hemolytic anemia, where the body's immune system mistakenly identifies its own red blood cells as a foreign substance and attacks them. Excessive hemolysis (red blood cell breakdown) can occur for many reasons, including:
- Certain drugs - some antibiotics, for instance
- Snake or spider venom
- Toxins produced through advanced kidney or liver disease
- Autoimmune attack - for instance hemolytic disease
- Severe hypertension
- Vascular grafts and prosthetic heart valves
- Clotting disorders
- Enlargement of the spleen
Symptoms of anemia
The most common symptom of anemia, regardless of type, is a feeling of fatigue and a lack of energy. Other common symptoms of anemia may include:
- Paleness of skin
- Fast or irregular heartbeat
- Shortness of breath
- Chest pain
In mild cases of anemia, individuals have little to no symptoms. Some forms of anemia can have specific symptoms unique to their type:
- Aplastic anemia - fever, frequent infections, and skin rashes
- Folic acid deficiency anemia - irritability, diarrhea, and a smooth tongue
- Hemolytic anemia - jaundice, dark colored urine, fever, and abdominal pains
- Sickle cell anemia - painful swelling of the feet and hands, fatigue, and jaundice
Diagnosis of anemia
A complete blood count can help diagnose anemia.
To diagnose anemia, several methods can be used; the most common of which is a complete blood count (CBC), which measures a number of blood components, including the patient's hemoglobin and hematocrit levels (ratio of the volume of red blood cells to the total volume of blood).
No special preparation is needed for this test, and only a small blood sample is required.
A CBC can be an indication of a patient's overall health and can detect other conditions, such as leukemia or kidney disease.
A doctor can examine the results of a CBC and compare them with the recommended healthy levels. What constitutes a healthy level may differ depending on sex, race, and age.
Unfortunately, a complete blood count does not offer a definitive diagnosis of anemia. It is possible to be outside the normal range but still healthy.
If the red blood cell, hemoglobin, and hematocrit levels are all below "normal," then anemia is likely.
A doctor may also perform a physical exam and ask for information regarding the patient's family medical history.
Treatments for anemia
There is a range of treatments for anemia, all ultimately aimed at increasing the red blood cell count which in turn increases the amount of oxygen the blood carries.
Depending on the type of anemia, the treatment has to match the cause:
- Iron deficiency anemia - iron supplements or dietary changes. If the condition is due to loss of blood, the bleeding must be found and stopped.
- Vitamin deficiency anemias - treatments include dietary supplements and B-12 shots.
- Thalassemia - blood transfusions, folic acid supplements, removal of the spleen and, sometimes, blood transfusions and bone marrow transplants.
- Anemia of chronic disease - this is anemia associated with a serious, chronic underlying condition; there are no specific treatments. The focus is on the underlying condition.
- Aplastic anemia - blood transfusions or bone marrow transplants.
- Sickle cell anemia - administering oxygen, pain relief, and intravenous fluids. Other treatments could include antibiotics, folic acid supplements, and blood transfusions. A cancer drug known as Droxia or Hydrea is also used.
- Hemolytic anemias - avoiding suspect medication, treating infections, immunosuppressant drugs. Plasmapheresis (blood-filtering) might be necessary in some cases.
If the anemia is caused by nutritional deficiencies, a change to an iron-rich diet can help alleviate the symptoms. The following foods are high in iron:
- Iron-fortified cereals and breads
- Dark-green leafy vegetables, for instance, curly kale and watercress
- Pulses and beans
- Brown rice
- White and red meats
- Nuts and seeds
- Dried fruits, including apricots, raisins, and prunes
Risk factors for anemia
Anemia can occur in people of all ages and race, males and females. However, there are certain factors that raise the risk for anemia:
- Women of childbearing age - due to menstruation
- Pregnancy and childbirth - due increased demands of iron, women should supplement with folic acid
- Preterm infants
- Children aged 1-2
- Individuals with poor diets, low in vitamins, mineral, and iron
- Blood loss from surgery or injury
- Long-term or serious illnesses, such as AIDs, diabetes, kidney disease, cancer, rheumatoid arthritis, heart failure, and liver disease
- A family history of inherited anemias, such as sickle cell anemia
- Intestinal disorders-affects absorption of nutrients