What Is Sickle Cell Anemia

what is sickle cell anemia
Anemia is characterized by an insufficient amount of red blood cells or hemoglobin (iron rich protein) in the blood. The red blood cells (erythrocytes) contain hemoglobin, which is responsible for carrying oxygen from the lungs to other parts of the body. There are several causes of anemia including blood loss, abnormal red blood production, and red blood cells destruction. 

Sickle Cell Anemia


Sickle cell anemia is a very common (affects 70,000 to 100,000 Americans) blood disorder that has several different characteristics.

Abnormal red blood cells contain hemoglobin S, which causes

These cells to form in a sickle or crescent shape

They stick together and form long, rod like structures

Sickle cells cannot travel normally through blood vessels, like normal RBCs

They also block the blood vessels, which restricts normal blood flow throughout the body

Sickle cells only survive ten to twenty days


Human Blood


Human blood is composed of red blood cells (40-45%), plasma (water, sugar, fat, salt, protein), white blood cells (disease fighting), and platelets. Blood has many responsibilities including:

Transportation of oxygen and nutrients

Prevents excessive blood loss by forming blood clots

Transports waste products to the kidneys (urea) and liver to be filtered and cleaned

Body temperature regulation

Normal RBCs look like a donut, without a hole and they can survive up to 120 days, unlike the sickle cells. Hematopoiesis is the formation of red blood cells, which takes place in the blood marrow of the long bones. RBCs are produced at a rate of two million/second.

Since sickle cells do not survive longer than twenty days, the body cannot possibly keep up with the production needs, which is what causes the anemia.


Signs And Symptoms


When the sickle cells block the blood vessels individuals will begin to experience moderate to severe symptoms of the disorder.

Dyspnea (shortness of breath)


Acrocyanosis (extremities are cold to touch, with a bluish color)

Vertigo (dizziness)

Jaundice (yellow pigmentation) of the skin and sclera (whites of the eye ball)

Pallor complexion

It is not uncommon for an individual to experience a sickle cell crisis, which involves sudden onset of moderate to severe pain.

Bone Crisis involves pain in the long bones.

Joint Crisis involves painful joints and poor range of motion

Acute chest syndrome is characterized by angina (chest pain), hemoptysis (coughing up blood), and dyspnea

Abdominal crisis is characterized by abdominal pain, nausea, vomiting, and diarrhea




Sickle cell anemia is most often diagnosed by one type of blood test, hemoglobin S. This test identifies the presence of hemoglobin S and the number of RBCs and hemoglobin level in the blood.




Sickle cell anemia can sometimes be treated with a allogeneic transplant (bone marrow). Prior to the transplant the individual is administered chemotherapy and sometimes radiation. The donor is most often a family member. This type of treatment can last over several weeks to months.

Other forms of treatment include pain management and hydroxyurea. Hydroxyurea is an oral medication that boosts the body’s production of fetal hemoglobin (hemoglobin F). This drug has been scientifically tested and is effective in reducing the sickle cell crisis incidents and the need for red blood cell transfusions. Individuals taking hydroxyurea must undergo routine blood testing


Major Complications Associated with Sickle Cell Anemia


Sickle cell anemia can potentially cause organ (kidney, liver) damage and make individuals at a higher risk for infection, eye damage (retinopathy), myocardial infarction (heart attack) and CVA (stroke).

It is not uncommon for men to suffer with priapism (prolonged erection).


Factors Of Acute Sickle Cell Crisis


There are several factors that may be linked to the onset of an acute sickle cell crisis.

Dehydration (extreme loss of body water)

Infection (pneumonia)

Excessive Drug and Alcohol use


Extreme Stress

Blood Loss




Sickle cell anemia is a genetic disorder, where the individual will inherit a sickle cell from each parent. Sickle cell trait (not the disease) is when the individual will inherit one sickle cell gene from one parent and a normal gene from the other. Hemoglobin SC is when the individual inherits a sickle cell gene from one parent a different abnormal gene from the other.

An individual with the sickle cell trait will not exhibit symptoms of the disorder but acts as a carrier and can pass it on to their children.


Genetic Testing


Genetic testing for sickle cell anemia has become a normal part of the newborn screening process in the United States. A DNA screening involves the collection of blood, skin, bone, or other body tissues, which and be used in the testing for genetic diseases. Chorionic villus sampling (first trimester) and amniotic fluid sampling (amniocentesis, second & third trimester) may also be required to get a better diagnosis.