Table of Contents
Definition of Anemia
Anemia is a medical condition that results from a shortage in the proportion of red blood cells so that there isn’t enough of them to meet the physiologic requirements of the body. Red blood cells contain hemoglobin which is responsible for transporting oxygen around the body.
A decrease in the number of red blood cells means that the volume of oxygen-rich blood is reduced. This results in issues such as tiredness, dizziness, headaches and difficulty in breathing. Prolonged anemia can result in injury to the body’s major organs including the heart and brain, among others. In severe cases, anemia can lead to death.
Etiology and Classification of Anemia
The broad categories of anemia include:
- Anemia caused by excessive blood loss
- Inefficient production of red blood cells
- Anemia that results from a chronic disease
- Anemia caused by extreme destruction of red blood cells.
Anemia due to excessive blood loss
Extreme loss of blood can lead to anemia through several mechanisms. While it is known that acute bleeding can lead to anemia, it is easy to overlook chronic hemorrhage, because it is difficult to spot. The culprits for chronic blood loss include bleeding ulcers, hemorrhoids, colon cancer, parasite infection, menstruation, pregnancy or sustained utilization of nonsteroidal anti-inflammatory drugs (NSAIDS), among others.
Inefficient production of red blood cells
There are certain natural and acquired conditions and situations that can inhibit the body’s ability to produce enough red blood cells. Poor eating habits (deficiency of iron, folic acid, Vitamin B12), inconsistent hormone quantities (erythropoietin), chronic illnesses and pregnancy are some of the acquired conditions that can lead to anemia. An acquired or inherited condition that can inhibit the production of optimal values of red blood cells is Aplastic anemia.
Anemia resulting from chronic disease
Several chronic medical problems lead to anemia. The most common one is cancer, especially cancers of the blood such as leukemia or lymphoma. In fact, anemia can be a pointer to blood cancer, and often an anemic patient may eventually be diagnosed with cancer. In such cases, anemia results when the tumor cells heighten the blood producing bone marrow, leading to a situation where they can no longer meet the body’s need for blood.
Furthermore, individuals with chronic kidney disease develop anemia, because of the kidney’s inability to manufacture the required amount of erythropoietin needed to stimulate the production of red blood cell.
Anemia caused by extreme destruction of red blood cells
Enlargement of the spleen leads to extreme destruction of red blood cells, but this can sometimes be corrected by removing the spleen (splenectomy). Hemolytic anemia results from self-destruction of the red blood cells owing to pressure from the circulatory system.
There are some inherited conditions that may result in hemolytic anemia, while others, such as infections, medications, etc., are acquired. In some rare cases, autoimmune disorders can cause hemolytic anemia.
Pathophysiology of Anemia
Anemia results from a severe reduction of oxygen delivery to the tissues.
A complex but balanced system of oxygen supply and demand makes the body’s tissues and organs function optimally.
On the other hand, delivery of oxygen to body tissues is determined by hemoglobin volume, blood volume, health of the cardiovascular and pulmonary system and oxygen saturation.
Any inherited or acquired disease condition that affects the above factors can lead to anemia.
Poor or inadequate delivery of oxygen to the tissues can derail the process of erythropoiesis, leading to inadequate production of red blood cells in the body.
Clinical features of Anemia
The type of anemia, cause of anemia, severity and background health problems including bleeding, cancer and chronic kidney disease are the determinants of the signs and symptoms of anemia.
Symptoms of anemia
The general symptoms may include:
- Getting tired easily and weakness.
- Difficulty breathing and shortness of breath on carrying out activities.
- Increased heartbeat
- Dizziness and/or headache
- Tinnitus (feelings of ringing in the ears)
- Mood swings
- Paleness of the skin
- Loss of libido (sexual drive).
Signs of Anemia
1. Musculoskeletal disorder and weight gain:
- Effort capacity is decreased
- Exercise limitation
2. Cardiovascular signs:
- Increased cardiac output
- Congestive Cardiac Failure
3. Immune system dysfunction:
- Decreased resistance against infections
- T-lymphocyte and polymorphonuclear leukocyte dysfunction
4. Gastrointestinal system signs:
- Loss of appetite
5. Neurological signs:
- Sleep disturbance
- Attention deficit
- Behavioral disorder
Investigations of Anemia
Physical examination is paramount to ascertain if the individual is presenting with any symptoms of anemia along with any complications. Since anemia may be the initial symptom of a debilitating condition, evaluating the cause is imperative. This may not be easy to do when the patient is elderly, malnourished, suffering from a chronic disease or whose anemia is a result of several illnesses. It is essential for the physician to carry out an in-depth medical, personal and dietary history. This should include:
- Family or previous personal history of anemia
- Previous history of gallbladder disease, jaundice or enlarged spleen
- History or present heavy menstruation in women
- Bloody stool or signs of internal bleeding
- Dietary history in the elderly and poor, or both.
While there are several means of diagnosing anemia, the most readily available diagnostic test is a Complete Blood Count (CBC). A complete blood count (CBC) is a cocktail of tests that is meant to provide information about the size, quantity and shape of red blood cells. The CBC also provides information on the volume of white blood cells and platelets. A Complete Blood Count involves the evaluation of hemoglobin, hematocrit and mean corpuscular volume.
Hemoglobin is the iron and oxygen-carrying constituent of blood. The normal value for hemoglobin is dependent on the age and gender of the child. Anemia is diagnosed when the amount of hemoglobin falls below 12 g/dL for non-pregnant women and 13 g/dL for men. To determine the severity of anemia, the concentration of hemoglobin is categorized as follows:
- Mild anemia is queried when hemoglobin is between 9.5–13.0 g/dL
- Moderate anemia is suspected when hemoglobin is between 8.0–9.5 g/dL
- Severe anemia is diagnosed when concentrations of hemoglobin is below 8.0 g/dL
Hematocrit is the proportion of red blood cells in the blood. A child with a normal blood count and a high plasma volume may still be anemic because of the high volume of blood cells that have been diluted. The normal hematocrit value depends on the child’s age and gender. The range of hematocrit that is used to determine the severity of anemia is:
- Children aged 6 months – 5 years: Below 33 %
- Children aged 5 years –12 years: Below 35 %
- Children aged 12 years –15 years: Below 36 %
Mean corpuscular volume
Mean corpuscular volume (MCV) measures the mean size of red blood cells and is based on the premise that larger red blood cells (macrocytic) are a sign of anemia resulting from a deficiency of Vitamin B12, while microcytic (or smaller red blood cells) result from iron deficiency.
Direct and indirect Coombs test
The Coombs test is used as part of the diagnosis for anemia, specifically to determine what type of anemia a person is suffering from. It checks if the body is producing the necessary antibodies to fight diseases that may invade the system. A Coombs test will also reveal if the body’s antibodies are attacking its own red blood cells, as this can result in hemolytic anemia. There are two types of Coombs test: the direct Coombs test and the indirect Coombs test.
The direct test or direct antiglobulin test (DAT) is used to confirm a suspected case of autoimmune destruction of red blood cells, while the indirect test (indirect antiglobulin test, IAT) is used to detect in-vitro reactions within the body’s antibody-antigen system. It is also used to check for any issues during blood transfusions as well as screen expectant mothers for the risk of their fetus developing hemolytic disease of the newborn.
Management of Anemia
The management of anemia is determined by the etiology, type and severity of the condition. Before establishing a course of therapy for anemia, the following should be taken into consideration:
The aim of confirming the exact cause of an anemia is to allow the physician to come up with a specific and effective treatment. For instance, corticosteroids are more effective in the treatment of autoimmune hemolytic anemia than other medications.
Also, the therapy and medical management of different types of hereditary disorders vary greatly. For example, while splenectomy is effective in managing hereditary spherocytosis and hereditary elliptocytosis, it is not advantageous in treating other hereditary hemolytic disorders.
Another effective approach to managing anemia is to withdraw medications that can produce aplasia or restrict the maturation of the erythrocytes’ precursors.
Also, any diseases that are related to the anemia should be treated accordingly.
Diets and Supplements for diagnosed Anemia
Poor diet or certain conditions result in decreased supply of essential vitamins or iron to the body, leading to anemia.
To improve your supply of vitamins and iron, your physician may advice you to take more vitamin B12, Vitamin C and folic acid.
Furthermore, in cases where a patient is down with sideroblastic anemia, physicians may prescribe Pyridoxine, which has been found to be very effective.
For patients who are on a strict vegetarian diet, their diet must be supplemented with iron and vitamin B-12.
For patients with anemia resulting from iron deficiency, the following diet choices can be suggested:
- Red meat, such as beef, lamb, pork, as well as kidneys, liver, heart (note: pregnant women should not consume liver).
- Fish and shellfish
- Cereal and cereal products
- Nuts and seeds
- Green leafy vegetables
- Beans and pulses
- Dried fruit
For anemia induced by Folic acid deficiency, the following diet can be suggested:
- Fresh, raw or cooked, Brussels sprouts, broccoli, kale, spinach, among others
- Boiled black-eyed beans and chickpeas
- Breakfast cereals containing folic acid
- Liver (note, pregnant women should avoid liver)
- Kidneys, yeast and beef extracts
The following foods contain good amounts of Vitamin B12:
- Liver/liver pâté (note pregnant women should avoid liver and derived products)
- and several others.
Medical Treatment of Anemia
Medications to boost the body’s ability to produce more red blood cells may be prescribed to treat the cause of anemia. Some of the drugs include:
- Hormones in cases of heavy menstruation
- Artificial erythropoietin to boost the body’s ability to produce more red blood cells
- Drugs to safeguard your body’s immune system from attacking its own red blood cells
- Chelation therapy in cases of lead poisoning.
Blood Marrow Stem Cell Transplant
This procedure replaces any defective stem cells with healthy stem cells. Stem cells are what develop into red and white blood cells and platelets.
The stem cells are accessed from a donor.
For patients with anemia resulting from leukemia, lymphoma, Hodgkin lymphoma, multiple myeloma, myelofibrosis and aplastic disease, bone marrow and stem cell transplantation have been used effectively and with excellent outcomes.
For example, the rate of mortality has been reduced, resulting in good survival rates along with a correction of hematologic abnormalities.
Individuals suffering from severe anemia need to reduce their activity levels until their anemia is at least partly treated.
Blood transfusion may be avoided if bed rest is ordered early before the initiation of therapy, especially in patients whose anemia can be reversed (for example, those with pernicious anemia).
On rare occasions, young men develop a form of hemolytic anemia called March hemoglobinuria, which results from steeping on or running on hard surfaces. This can be managed by restricting the triggering activity or exercise (for instance running on a softer surface such as grass, rather than on a hard surface like concrete) and utilizing appropriate shoes while engaging in these activities.
While there are no explicit surgical interventions for the management of anemia, the indication of surgery depends on the etiology of anemia.
If the cause of a patient’s anemia is a colon or uterine cancer that is slowly bleeding, then the tumor has to be surgically removed to treat the anemia.
Also, if the body is self-destroying its red blood cells, the spleen has to be removed if it is enlarged or diseased.
Complications of Anemia
Prognosis of anemia is good in most cases. However, complications may arise in some cases due to multiple organ dysfunction or manifestation of dysfunctional systems. Possible complications might include:
- Congestive Cardiac Failure (CCF)
- Risk of infection
- Attention deficit
- Lead intoxication
- Developmental disorders
- Intellectual Disability (ID)