Sickle cell anemia is an inherited form of anemia - a condition in which there aren't enough healthy red blood cells to carry adequate oxygen throughout your body. Normally, your red blood cells are flexible and round, moving easily through your blood vessels. In sickle cell anemia, the red blood cells become rigid, sticky and are shaped like sickles or crescent moons. These irregularly shaped cells can get stuck in small blood vessels, which can slow or block blood flow and oxygen to parts of the body.

Alternative Names of Sickle Cell are: Hemoglobin SS disease; Hemoglobin S disease; HbS disease; Sickle cell disorders; Sickling disorder due to hemoglobin S; Sickle cell disease

Complications of Sickle Cell

Sickle cell anemia can lead to a host of complications, including:

• Stroke. A stroke can occur if sickle cells block blood flow to an area of your brain. Stroke is one of the most serious complications of sickle cell anemia. Signs of stroke include seizures, weakness or numbness of your arms and legs, sudden speech difficulties, and loss of consciousness. If your baby or child has any of these signs and symptoms, seek medical treatment immediately. A stroke can be fatal.
• Acute chest syndrome. This life-threatening complication of sickle cell anemia causes chest pain, fever and difficulty breathing. Acute chest syndrome can be caused by a lung infection or by sickle cells blocking blood vessels in your lungs. It requires emergency medical treatment with antibiotics, blood transfusions and drugs that open up airways in your lungs. Recurrent attacks can damage your lungs.
• Pulmonary hypertension. About one-third of people with sickle cell anemia will eventually develop high blood pressure in their lungs (pulmonary hypertension). Shortness of breath and difficulty breathing are common symptoms of this condition, which can ultimately lead to heart failure.
• Organ damage. Sickle cells can block blood flow through blood vessels, immediately depriving an organ of blood and oxygen. In sickle cell anemia, blood is also chronically low on oxygen. Chronic deprivation of oxygen-rich blood can damage nerves and organs in your body, including your kidneys, liver and spleen. Organ damage can be fatal.
• Blindness. Tiny blood vessels that supply your eyes can get blocked by sickle cells. Over time, this can damage the retina - the portion of the eye that processes visual images - and lead to blindness.
• Skin ulcers. Sickle cell anemia can cause open sores, called ulcers, on your legs.
• Gallstones. The breakdown of red blood cells produces a substance called bilirubin. Bilirubin is responsible for yellowing of the skin and eyes (jaundice) in people with sickle cell anemia. A high level of bilirubin in your body can also lead to gallstones.
• Priapism. Men with sickle cell anemia may experience painful erections, a condition called priapism. As occurs in other parts of the body, sickle cells can block the blood vessels in the penis. This can damage the penis and eventually lead to impotence.

Causes of Sickle Cell

Sickle cell anemia is caused by a mutation in the gene that tells your body to make hemoglobin — the red, iron-rich compound that gives blood its red color. Hemoglobin is a component of every red blood cell. It allows red blood cells to carry oxygen from your lungs to all parts of your body, and to carry carbon dioxide waste from throughout your body to your lungs so that it can be exhaled. Under normal circumstances, your body makes healthy hemoglobin known as hemoglobin A. People with sickle cell anemia make hemoglobin S — the S stands for sickle. The sickle cell gene is passed from generation to generation in a pattern of inheritance called autosomal recessive inheritance. This means that both the mother and the father must pass on the defective form of the gene for a child to be affected. People with sickle cell trait have one normal hemoglobin gene and one defective form of the gene. So their bodies make both normal hemoglobin and sickle cell hemoglobin. Their blood may contain some sickle cells, but they generally don't experience symptoms. However, they are carriers of the disease, which means they can pass the defective gene on to their children. With each pregnancy, two people with sickle cell traits have:

• A 25 percent chance of having an unaffected child with normal hemoglobin
• A 50 percent chance of having a child who also is a carrier
• A 25 percent chance of having a child with sickle cell anemia

Signs & Symptoms of Sickle Cell

The signs and symptoms of sickle cell anemia vary. Some people have mild symptoms. Others have very severe symptoms and often are hospitalized for treatment. Sickle cell anemia is present at birth, but many infants don't show any signs until after 4 months of age. The most common signs and symptoms are linked to anemia and pain. Other signs and symptoms are linked to the disease's complications.

Signs and Symptoms Related to Anemia

The most common symptom of anemia is fatigue (feeling tired or weak). Other signs and symptoms of anemia include:

• Shortness of breath
• Dizziness
• Headache
• Coldness in the hands and feet
• Pale skin
• Chest pain

Signs and Symptoms Related to Pain

• Sudden pain throughout the body is a common symptom of sickle cell anemia. This pain is called a "sickle cell crisis." Sickle cell crises often affect the bones, lungs, abdomen, and joints.
• A sickle cell crisis occurs when sickled red blood cells form clumps in the bloodstream. (Other cells also may play a role in this clumping process.) These clumps of cells block blood flow through the small blood vessels in the limbs and organs. This can cause pain and organ damage.
• The pain from sickle cell crises can be acute or chronic, but acute pain is more common. Acute pain is sudden and can range from mild to very severe. The pain usually lasts from hours to a few days. Chronic pain often lasts for weeks to months. Chronic pain can be hard to bear and mentally draining. This pain may severely limit your daily activities.
• Almost all people who have sickle cell anemia have painful crises at some point in their lives. Some have these crises less than once a year. Others may have 15 or more crises in a year.
• Many factors can play a role in a sickle cell crisis. Often, more than one factor is involved and the exact cause isn't known. You can control some factors. For example, your risk for a sickle cell crisis increases if you're dehydrated (your body doesn't have enough fluid). Drinking plenty of fluids can lower your risk for a painful crisis. Other factors, such as an infection, you can't control.
• Painful crises are the leading cause of emergency room visits and hospitalizations of people who have sickle cell anemia.

Diagnosis of Sickle Cell

• A blood test can check for hemoglobin S - the defective form of hemoglobin that underlies sickle cell anemia. In the United States, this blood test is part of routine newborn screening done at the hospital. But older children and adults can be tested too.
• In adults, a blood sample is drawn from a vein in the arm. In young children and babies, the blood sample is usually collected from a finger or heel. The sample is then sent to a laboratory, where it's screened for hemoglobin S.
• If the screening test is negative, there is no sickle cell gene present. If the screening test is positive, further tests will be done to determine whether one or two sickle cell genes are present. People who have one gene - sickle cell trait - have a fairly small percentage of hemoglobin S. People with two genes - sickle cell disease - have a much larger percentage of the defective hemoglobin.

Treatments of Sickle Cell

Bone marrow transplant offers the only potential cure for sickle cell anemia. But, finding a donor is difficult and the procedure has serious risks associated with it, including death. As a result, treatment for sickle cell anemia is usually aimed at avoiding crises, relieving symptoms and preventing complications. If you have sickle cell anemia, you'll need to make regular visits to your doctor to check your red blood cell count and monitor your health. Treatments may include medications to reduce pain and prevent complications, blood transfusions and supplemental oxygen, as well as bone marrow transplant.

Medications

Medications used to treat sickle cell anemia include:

• Antibiotics.
• Pain-relieving medications.
• Hydroxyurea (Droxia, Hydrea).

Prevention of Sickle Cell

If you carry the sickle cell trait, you may wish to see a genetic counselor before trying to conceive a child. A genetic counselor can help you understand your risk of having a child with sickle cell anemia. He or she can also explain possible treatments, preventive measures and reproductive options.

There is an in vitro fertilization procedure that improves the chances for parents who both carry the sickle cell gene to have a child with normal hemoglobin. This procedure is known as preimplantation genetic diagnosis. First, eggs are taken from the mother. Then, sperm is taken from the father. In a laboratory, the eggs are fertilized with the sperm. The fertilized eggs are then tested for the presence of the sickle cell gene. Fertilized eggs free of the sickle cell gene can be implanted into the mother for normal development. However, this procedure is expensive and not always successful.

When to seek Medical Advice

Although sickle cell anemia is usually diagnosed in infancy, if you or your child develops any of the following problems, see your doctor right away or seek emergency medical care.

• Any signs or symptoms of stroke. If you notice any one-sided paralysis or weakness in the face, arms or legs, confusion, trouble walking or talking, sudden vision problems or numbness or a headache call 911 or your local emergency number right away.
• Swelling in the hands or feet.
• Abdominal swelling, especially if the area is tender to touch.
• Fever. People with sickle cell anemia have an increased risk of infection, and fever can be the first sign of an illness.
• Pale skin or nail beds.
• Yellow tint to the skin or the whites of the eyes.