What is Anemia

What Causes Anemia?

Symptoms of Anemia

Different Kinds of Anemia

What is Anemia?

Anemia is a condition where there is an abnormally low number of red blood cells circulating in the body. It is the most common disorder of the red blood cells, affecting about 3.5 million Americans.

Anemia is not a disease. It is a condition that results from below-normal levels of hemoglobin in the red blood cells. Hemoglobin is the iron-containing pigment of the red blood cells that carries oxygen from the lungs to the tissues.

There are many different kinds of anemia (SEE BELOW), each with its own cause. For example, a poor diet can cause anemia. The more severe types of this condition are often inherited.

Why Does Anemia Occur?

To understand why anemia occurs, it's important to understand the function of blood itself. Blood is a mixture of plasma (the fluid part of the blood) and cells. Its red color comes from the predominant cells found in the blood, called erythrocytes.

A healthy person has about 5 million red cells in every cubic millimeter of blood. Each cell contains a protein (hemoglobin) that carries oxygen through the body.

The process of creating and recycling red blood cells is exceptionally complex. Trouble can occur at any point in this process. If the red blood cells fail to effectively transport oxygen throughout the body, anemia can result.

What Causes Anemia?

There are three general causes of anemia:

• Decreased red cell production by the bone marrow

• Increased red cell destruction, orhemolysis

• Blood loss from heavy menstrual periods or internal bleeding

When you're anemic, your body either produces too few healthy red blood cells, or destroys them faster than they can be replaced or loses too many of them. If your diet lacks certain vitamins and minerals, the production of hemoglobin can slow down.

Types of anemia caused by decreases in red cell production include iron deficiency anemia and vitamin deficient anemia.

If something in the body destroys or attacks red blood cells, the bone marrow tries to produce more blood. If the destruction of red blood cells is rapid, the marrow can't catch up. This problem is often inherited. The resulting anemia is called hemolytic anemia.

A severe bleeding episode can result in temporary anemia until the body has had time to make up the blood that was lost. But even small, persistent losses of blood may cause anemia if you have a poor diet. A healthy person whose diet contains plenty of iron and vitamins can produce large amounts of new blood, reducing the risk of anemia.

Symptoms of Anemia

A person with anemia will feel tired and weak because the body's tissues are being starved of oxygen. In fact, fatigue is the main symptom of most types of anemia. The severity of symptoms is in part related to the severity of anemia. Mild anemia can occur without symptoms and may be detected only during a medical exam that includes a blood test.

Symptoms of anemia include:

• Fatigue

• Weakness

• Fainting

• Breathlessness

• Heart palpitations (rapid or irregular beating)

• Dizziness

• Headache

• Ringing in the ears (tinnitus)

• Difficulty sleeping

• Difficulty concentrating

Common signs include:

• Pale complexion

• The normally red lining of the mouth and eyelids fades in color

• Rapid heartbeat (tachycardia)

• Abnormal menstruation (either absence of periods or increased bleeding)

Other signs depend on the cause of the anemia. These can include spoon-shaped finger nails and toenails in iron-deficiency anemia, mildjaundice in hemolytic anemias, and leg ulcers in sickle cell anemia .

Different Kinds of Anemia

There are different kinds of anemia. Some forms of this condition are inherited, while others are brought on by poor nutrition.

Iron Deficiency Anemia

The body needs iron to produce the hemoglobin necessary for red blood cell production. In general, most people need just 1 milligram of iron daily. Menstruating women need double that dose.

Vitamin Deficiency Anemias

Vitamin B-12 is also essential in hemoglobin production. Normally, a chemical secreted by the stomach helps the body absorbs this vitamin. However, some people can't readily absorb B-12. The result is B-12 deficiency (pernicious anemia). Because the symptoms develop gradually this condition may not be immediately recognized. Those with thyroid disease or diabetes mellitus are at increased risk for this type of anemia. The condition occurs most often in 40- to 80-year-old northern Europeans with fair skin.

A lack of folic acid, another one of the B vitamins, can also lead to anemia. Folic acid deficiency is a particular problem for alcoholics.

Hemolytic Anemias

Anemia caused by the premature destruction of red blood cells is known as hemolytic anemia. In this type of anemia, antibodies produced by the immune system damage red blood cells. This condition is sometimes associated with disorders such as systemic lupus, or lymphoma.

Toxic materials such as lead, copper, and benzene can also cause the destruction of red blood cells.

Blood transfusions may be necessary for some people with this kind of anemia. Hemolytic anemia can be acquired or inherited. Sickle cell disease and thalassemia are both inherited types of hemolytic anemia.

Sickle Cell Anemia

Sickle cell anemia is also known as Hemoglobin S disease. This is a serious, life-threatening inherited form of anemia. Persons with this disease have sickle-shaped red blood cells that are stiff and unable to squeeze through blood vessels.

Persons with this disease often suffer from pain in the joints and bones. Infections and heart failure can also occur.

The disease occurs in just 0.6 percent of the population, usually in African Americans.

Thalassemia

This is a group of anemias due to the defects in the genes producing hemoglobin. It is most common in people of Mediterranean descent. There are two major forms: thalassemia minor and thalassemia major.

As its name implies, thalassemia minor is mild and those suffering from this condition go on to live a full life. Treatment is often unnecessary. Thalassemia major can be serious, but it is very rare. Transfusions or bone marrow transplants are usually required. Thalassemia major is also called Cooley's anemia, named after the doctor who first described it in 1925.

Aplastic Anemia

This is one of the deadliest and most rare forms of anemia. Only two to six people per million have this type of anemia. The condition results from an unexplained failure of the bone marrow to produce all types of blood cells. Instead, fat cells replace bone marrow.

Aplastic anemia is usually found in adolescents and young adults. Symptoms can include bleeding in the mucous membranes. Chemicals such as benzene and certain pesticides can also cause this type of anemia.