Sickle cell anemia is an inherited condition in which the red blood cells become abnormally shaped. It may lead to pain or a number of other serious complications, including stroke, life-threatening infection or end-organ damage. The disease is present at birth, and symptoms typically begin early in childhood.

Red blood cells transport vital oxygen to the limbs and organs. These cells are normally disc-shaped. In people with sickle cell anemia, a large number of these red blood cells become sickle- or crescent-shaped. This sickle-shape is caused by the presence of an abnormal hemoglobin called hemoglobin S. Hemoglobin, a protein molecule present in all red blood cells, is responsible for transporting oxygen from the lungs to the tissues around the body. Normally red blood cells contain hemoglobin A. With hemoglobin S, the amount of oxygen transported in the red blood cells is reduced.

As a result of the reduced oxygen, the cells change shape. These sickle-shaped cells are harmful because they often get stuck in small blood vessels, obstructing the flow of blood. This can lead to a number of complications, including recurrent episodes of pain known as sickle cell crises, although this term is falling out of favor among the medical establishment.

These structurally abnormal cells also become very fragile and are broken down prematurely, at a rate faster than the body can replace them. While a normal red blood cell typically lives for about 90 days, a sickle cell typically lasts only 16 days. As a result, patients with sickle cell anemia often have a lower-than-normal number of red blood cells in their blood, a condition called anemia. This can lead to a number of symptoms, including fatigue, jaundice (yellowing of skin and eyes), shortness of breath, and delayed growth and development in children.

Sickle cell anemia can only affect someone who has inherited hemoglobin S from both parents. A person who inherits hemoglobin S from only one parent can have sickle cell trait. Known as carriers, these people with sickle cell trait usually have no symptoms. They can, however, pass the trait on to their children.

To determine if a person has sickle cell anemia or sickle cell trait, physicians may order a number of blood tests (e.g., hemoglobin electrophoresis, sickle cell test). Newborns are routinely screened for the abnormal gene in many states. Adults, older children and fetuses can also be screened.

According to the Sickle Cell Disease Association of America, there are approximately 70,000 people living with sickle cell anemia in the United States. Most of these patients are African-American and Hispanic.

Currently, bone marrow transplant is the only cure for sickle cell anemia. However, the procedure is risky, and it is often difficult to find a suitable bone marrow donor. When a bone marrow transplant is not an option, the focus of treatment is on relieving pain and preventing crises (recurrent episodes of pain) and other complications.

Common treatment methods include medication, especially with hydroxyurea, (to control pain and reduce the number of crises), vaccinations and blood transfusions. A number of additional treatment methods are also being studied that may cause the body to produce more hemoglobin, such as the use of hydroxyurea.  

In the past, people with sickle cell anemia often died between the ages of 20 and 40, usually because of organ failure. However, medical advancements have enabled most people with sickle cell anemia to live well into their 40s and 50s.

Couples in which both partners carry the sickle cell gene may be able to lower the risk of having a child with sickle cell anemia with an in vitro fertilization technique known as preimplantation genetic diagnosis. This procedure allows physicians to implant eggs that are free of the defective gene into a woman for development.

Sickle cell anemia is an inherited blood disorder. It affects the red blood cells, resulting in pain and a number of other complications. The disease is present at birth, and symptoms typically begin early in childhood. Studies have indicated that 96 percent of children who were diagnosed with sickle cell anemia at birth have experienced symptoms by eight years of age. According to the Sickle Cell Disease Association of America, there are approximately 1,000 babies born with the disease each year and more than 70,000 people living with the disease in the United States. Although complications such as infection and organ damage can be fatal, most patients with sickle cell anemia live into their 40s and 50s, whereas, in the past, the life expectancy was often between 20 and 40.

Diseases caused by sickle cell trait caused damage in two ways. First, patients suffer from vasoocclusive events. This means that the abnormally shaped blood cells block vessels in the body. There is some controversy about why the sickle-shaped cells provoke these events. Whatever the reason, during a vasoocclusive event, the flow of blood is restricted to the tissues beyond the blocked area. This can result in bouts of acute, intense pain. Oftentimes, this is the first symptom of sickle cell anemia, especially in the hands and feet.

Second, sickle cell diseases result in a shortage of red blood cells in the blood, a condition known as anemia. A normal red blood cell survives for about 90 days. A sickle-shaped blood cell, however, may survive for only 16 days before it is destroyed. Thus, the blood's overall oxygen-carrying capacity is reduced and the number of red blood cells is depressed.

Red blood cells are produced in the bone marrow, the soft inner component of bones. They contain hemoglobin, an iron-rich protein molecule that picks up oxygen from the lungs and releases it to the tissues as blood travels through the body. In healthy individuals, the body produces normal hemoglobin (hemoglobin A). In people with sickle cell anemia, red blood cells mostly contain an abnormal form of hemoglobin known as hemoglobin S. Hemoglobin S reduces the amount of oxygen in the cells.

In addition, there are other sickle cell diseases (SCDs), or hemoglobinopathies, in which symptoms may resemble those of sickle cell anemia but are generally milder. These related disorders include hemoglobin C disease, hemoglobin SC disease, sickle beta-plus thalassemia and sickle beta-zero thalassemia. The National Institutes of Health says that SCD is the nation’s most common inherited blood disorder.

Sickle cell anemia is an inherited disorder in which a child inherits one abnormal gene from each parent. This is known as autosomal recessive inheritance. These abnormal genes produce an abnormal type of blood hemoglobin called hemoglobin S.

In most cases, parents of a child with an autosomal recessive disorder do not themselves show signs of the disorder. Instead, they have one normal hemoglobin gene (which makes healthy hemoglobin A) and one abnormal hemoglobin gene (which makes unhealthy hemoglobin S). These people have more normal hemoglobin than abnormal hemoglobin, which prevents them from getting sickle cell anemia. When people carry the gene for sickle cell anemia but do not have the disease, they are said to have sickle cell trait.

Although their blood may contain some sickle cells, people with sickle cell trait are generally healthy and do not usually experience signs and symptoms of sickle cell anemia. Most live normal lives. However, people with sickle cell trait can pass the gene on to their children, who may then develop sickle cell anemia. The Sickle Cell Disease Association of America (SCDAA) estimates that 2.5 million Americans have the sickle cell trait.

According to the National Heart, Lung and Blood Institute (NHLBI), any child born to two people with the sickle cell trait has:

• A 25 percent chance of inheriting two sickle cell genes and having sickle cell anemia
  
  
• A 25 percent chance of inheriting two normal genes and not having the disease or the trait
  
  
• A 50 percent chance of inheriting one normal gene and one sickle cell gene, and having sickle cell trait

According to the SCDAA, when one parent has sickle cell anemia and the other has sickle cell trait, there is a 50 percent chance with each pregnancy that the child will have the disease and 50 percent chance they will have the trait. 

Sickle cell anemia affects millions of people around the world. However, the disease is more common among certain ethnic groups. Sickle cell trait is commonly found in people of African, Hispanic (e.g., from South America, Cuba, Central America), Mediterranean (e.g., from Turkey, Greece, Italy), Middle Eastern and Indian descent. In the United States, the disease most often affects African-Americans and Hispanics.

According to the NHLBI, approximately one in 12 African-Americans carry the sickle cell trait, and the disease occurs in about one in every 600 African-American births. In comparison, the disease occurs in one of every 1,000 to 1,400 Hispanic-American births.

Sickle cell anemia can cause a variety of signs and symptoms. The severity of these symptoms varies sharply from patient to patient. Some patients may experience mild symptoms while others may have symptoms severe enough to require hospitalization.

Anemia is a common symptom of this condition. It occurs when a person has a lower-than-normal number of red blood cells in their blood, resulting in too little oxygen in the body and a lack of energy. This can lead to symptoms such as fatigue, jaundice (yellowing of skin and eyes), shortness of breath, and delayed growth and development in children.

The most common initial symptom among people with sickle cell anemia is pain, usually in the hands and/or feet. The pain may be acute (the most common type, usually lasting from hours to days), chronic (lasting three to six months or longer) or a combination of both. Pain commonly experienced by people with the disease includes:

• Bone pain and joint pain
• Abdominal pain
• Chest pain
• Back pain
• Arm pain
• Leg pain

Other common signs and symptoms of sickle cell anemia include:

• Paleness (pallor)
• Rapid heart rate
• Fever
• Bloody urine (hematuria)
• Frequent urination (polyuria)
• Excessive thirst (polydipsia)

Although sickle cell anemia is present at birth, most people do not show symptoms of the condition until 4 months of age. Some people with the condition have mild symptoms, while others have severe symptoms that require hospitalization. People with sickle cell trait do not usually develop any signs and symptoms of sickle cell anemia, although they may develop a milder form of the disease. Areas with low oxygen, however, may trigger symptoms in people with the trait. This includes areas of high altitude such as mountains and flying in airplanes.

Blood vessels throughout the body are vulnerable to vasoocclusive episodes associated with sickle cell anemia. This helps explain the wide-ranging effects of this disease, including involvement of the cardiovascular, ocular and other organ systems. Typically, a vasoocclusive event causes pain because the tissues beyond the blockage in the blood vessel do not receive an adequate supply of blood. Typically, pain lasting anywhere from a few hours to weeks can occur in the back, ribs and limbs. Pain may also develop in the chest, abdomen and joints. In severe cases, hospitalization may be required so the patient may receive pain medications and intravenous (I.V.) fluids.

Though some patients experience painful episodes once every few years, others may have several episodes a year. After repeated episodes, a patient may develop damage to the kidneys, lungs, bones, eyes and central nervous system. These crises can be precipitated by infections. Opioid pain medications may be used to treat moderate to severe pain.

Common forms of crisis include:

• Hemolytic crisis. This crisis results from the rapid destruction of damaged red blood cells.
  
  
• Splenic sequestration crisis. This is the result of red blood cells suddenly becoming trapped in the spleen, resulting in an enlarged spleen and low blood volume.  Urgent medical care is necessary.
  
  
• Aplastic crisis. This is the result of infection (caused by the parvovirus B19) causing the bone marrow to stop producing red blood cells.  It is characterized by a sudden decrease in hemoglobin counts, requiring urgent blood transfusion.

Sickle cell anemia can lead to a number of other complications, some of which are life-threatening. Possible complications include:

• Hand-foot syndrome. Occurs when blood vessels in the hands and feet are blocked, causing swelling, pain and fever. One or both hands or feet may be affected, with swelling typically beginning on the back of the hands or feet before migrating to the fingers or toes. Hand-foot syndrome may be the first symptom experienced by infants with sickle cell anemia.
  
  
• Pulmonary hypertension. Occurs when high blood pressure occurs in the blood vessels that supply the lungs. Pulmonary hypertension occurs in one-third of patients with sickle cell anemia, according to the National Institutes of Health (NIH). It can lead to heart failure, although treatments can help to control symptoms.

• Stroke. A potentially fatal event in which the flow of oxygen-rich blood to the brain is reduced. In a person with sickle cell anemia, a stroke may occur as the result of sickle cells obstructing blood flow to the brain. Common signs of stroke include weakness or numbness in the limbs, especially on one side of the body, sudden difficulty speaking or swallowing, or alteration of consciousness.  They occur more commonly in children younger than 10 years old.
  
  In 2005, scientists unveiled a genetic test they described as 98 percent accurate in predicting strokes in people who have sickle cell anemia. The test detects variations in genes called single nucleotide polymorphisms (SNPs).
  
  
• Acute chest syndrome. A life–threatening condition that causes chest pain, fever and breathing difficulty. It is the result of a lung infection or sickle cells becoming trapped in the lungs, and it can be indistinguishable from pneumonia. Recurrent episodes can cause lung damage.   
  
  
• Organ damage. As blood travels throughout the body, it delivers oxygen to the organs. When sickle cells block blood flow through the blood vessels they deprive the organs of necessary oxygen. This may result in damage to nerves and organs, including the kidneys, liver and spleen. In some cases, organ damage may be fatal. Necrosis (tissue death) of the hip and shoulder joints may occur, causing considerable disability, and may require joint replacement surgery (arthroplasty).
  
  
• Blindness. In people with sickle cell anemia, sickle cells can obstruct the tiny blood vessels of the eyes. This can damage the retina (the component of the eye which processes visual images) and may lead to blindness.
  
  
• Ulcers. People with sickle cell anemia may develop open sores on their legs. Known as ulcers, these sores are the result of sickle cells blocking blood flow that nourishes the skin. This results in death of the skin cells and causes sores to develop.
  
  
• Gallstones. Bilirubin is a substance produced from the breakdown of red blood cells. People with sickle cell anemia may have high levels of bilirubin in their blood, which can lead to gallstones.  This may be present in up to 50 percent of adults with this disease.
  
  
• Impotence. In men, sickle cell anemia can lead to priapism (painful erections). This is the result of sickle cells preventing the blood from flowing out of an erect penis. According to the NIH, about 10 to 40 percent of men with sickle cell anemia experience priapism. The condition can damage the penis and cause impotence.
  
  
• Infection. Sickle cells can cause damage to the spleen, an organ responsible for fighting infection. As a result, people with sickle cell anemia are at an increased risk of infection including pneumonia, meningitis (inflammation of the membranes covering the brain and spinal cord), influenza, hepatitis (inflammation of the liver), cholecystitis (inflammation of the gallbladder), osteomyelitis (bone infection) and urinary tract infection. Pneumonia infection is the leading cause of death in children with sickle cell anemia.
  
  
• Stunted growth in children. The lower levels of red blood cells associated with sickle cell anemia prevent the body from getting the oxygen and nutrients needed for children to grow to full potential. Inadequate levels of red blood cells also can delay puberty in some children.

Many people carrying the sickle cell trait do not know that they have it. As a result, most states routinely screen all newborns for the disease. Screening is available by request in all other states. These tests reveal whether the infant has the disease or carries sickle cell trait. Diagnosis of the disease in infants is important because it ensures that the babies receive necessary treatment immediately.

Older children and adults can also be screened for sickle cell anemia and sickle cell trait. In adults, the required blood sample is usually drawn from a vein in the arm. In babies and young children, blood may be collected from a finger or heel prick. It is also possible to detect sickle cell anemia before birth by testing a sample of amniotic fluid (the fluid surrounding the fetus in the uterus) or tissue collected from the placenta.

The sickle cell test is a blood test used to determine whether a patient has the abnormal hemoglobin that causes sickle cell anemia (hemoglobin S) in their blood. A deoxygenation agent is added to the blood sample. When 25 percent or more of the hemoglobin is hemoglobin S, the red blood cells will structurally change into a sickle (crescent) shape. This occurrence indicates that the patient either has sickle cell anemia or has sickle cell trait.

In order to determine whether a patient has the disease or just carries the defective gene, the percentage of hemoglobin S in the blood has to be measured. Patients with sickle cell trait will have a small percentage of hemoglobin S in the blood, whereas people with sickle cell anemia will have a significantly larger percentage of the abnormal hemoglobin.   

To determine what types of hemoglobin are present in the blood, physicians will order a hemoglobin electrophoresis. During this test, electrical charges are sent through a solution of hemoglobin. Because different types of hemoglobin move different distances in response to an electric charge, the test can be used to differentiate normal hemoglobin (hemoglobin A) from hemoglobin S. Patients with significant levels of abnormal hemoglobin S may be diagnosed with sickle cell anemia in this manner.

Patients diagnosed with sickle cell anemia will be tested for anemia. A complete blood count will be ordered to determine the number of red blood cells in the blood. A number of additional tests may be ordered to check for other potential complications of the disease.

Children and adults with the disease may be referred to a hematologist, a physician who specializes in blood diseases. Carriers of sickle cell trait may be referred to a genetic counselor, a professional who specializes in genetic diseases. Such counselors can provide a carrier with information regarding their risk of having a child with sickle cell anemia. They can also explain treatment options, preventive measures and reproductive choices.

Bone marrow transplant is the only known cure for sickle cell anemia. Currently, however, it is recommended only for patients with severe symptoms and complications. The procedure carries many risks and is not always successful. In some cases the patient’s body may reject the bone marrow. It is also difficult to find suitable donors.

Before undergoing a bone marrow transplant, chemotherapy or radiation is used to destroy the recipient’s bone marrow. Surgery is then performed to remove healthy bone marrow from the matched donor. The collected bone marrow is placed in the patient’s body through a transfusion. As a result, the healthy bone marrow may begin to produce normal blood cells. 

A number of other treatment options are available. These treatments do not cure sickle cell anemia, but focus on relieving the symptoms, including the pain, and whenever possible interfering with the disease process.

Common treatment options include:

• Medications. A number of medications may be used to reduce pain and prevent complications including:
  
  
• Antibiotics. People with sickle cell anemia are vulnerable to infection. As a result, penicillin is often given to babies with sickle cell anemia when they are 2 to 4 months old. The drug is continued until the patient reaches 5 years of age. This helps prevent pneumonia and other life–threatening infections. Antibiotics may also be prescribed for adults with sickle cell anemia to treat infections.
  
  
• Folic acid.  In patients with this disease, a supplemental dose of folic acid should be taken because of chronic destruction of red blood cells. Folic acid can help create new red blood cells.
  
  
• Pain relievers. Patients may be able to relieve mild pain with over-the-counter pain medications. Physicians may prescribe stronger pain medications for more moderate to severe pain. Pain relievers commonly used with sickle cell anemia include acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs) and opioids.
  
  
• Hydroxyurea. Normally used to treat cancer, this drug may reduce the frequency of crises and acute chest syndrome when taken daily. It also reduces the need for blood transfusions. The drug appears to work by stimulating the production of fetal hemoglobin. Found in newborns, fetal hemoglobin prevents the formation of sickle cells. There is some concern, however, that use of this drug may increase the risk of tumors or leukemia. Patients should discuss these risks with their physician. This drug has not been approved for use in children.
  
  
• Vaccinations. Patients benefit from receiving regular vaccinations because they help prevent infections, a common complication of sickle cell anemia. Infants should receive all of the recommended vaccinations (e.g., measles, mumps, rubella). Children with sickle cells should receive an annual influenza shot, as well as vaccinations for pneumonia, meningitis and hepatitis. Adult patients should have annual influenza vaccinations and regular pneumonia vaccinations.
  
  
• Blood transfusions. During this procedure, red blood cells removed from donated blood are given intravenously to the patient. It is used to relieve anemia, which can cause jaundice and fatigue, by increasing the number of normal red blood cells. It may also be used to lower a patient’s risk of stroke. Recent research suggests that the 10 percent of sickle cell patients who are at high risk of stroke because of narrow blood vessels in the brain may need a lifetime of transfusions to lower their risk.
  
  
• Supplemental oxygen. Administered through a breathing mask, supplemental oxygen adds oxygen to the blood and improves breathing. It may be used during episodes of acute chest syndrome or a sickle cell crisis.

Because of the wide-ranging complications of sickle cell anemia, there are many possible treatment options in specific situations. Some of these specific complications include:

• Acute chest syndrome. This condition may be treated with oxygen therapy, transfusions, antibiotics and pain medications.
  
  
• Hand-foot syndrome. This condition may be treated with pain medication and fluids.
  
  
• Leg ulcers. These sores may be treated with cleansing solutions and zinc oxide. Treatment may also include pain medication, bedrest and keeping the leg raised to reduce swelling. In some cases, skin grafts may be necessary.
  
  
• Stroke. Depending on the type and severity of the stroke, patients may require surgery, medications or rehabilitation, such as physical therapy and occupational therapy. As noted above, blood transfusions may reduce the risk of stroke.
  
  
• Kidney disease. This complication may be treated with dialysis or a kidney transplant if end-stage.
  
  
• Priapism. Men experiencing priapism (painful erections) may need medications or surgery.
  
  
• Vision problems. Corrective lens, surgical procedures or low-vision rehabilitation may be used to treat eye or vision problems.
  
  
• Gallstone disease. Patients with gallstone disease may require surgery to remove the gallbladder.
  
  
• Damaged spleen. This condition may be treated with surgery (splenectomy).

There are a number of steps a physician may recommend that patients take to maintain their health and prevent pain episodes. These measures may include:

• Receiving immunizations and other treatments. In addition to antibiotic treatment, annual flu shots and vaccinations for pneumonia, meningitis, influenza and hepatitis may be helpful for children. Adults are urged to get annual flu shots and to be vaccinated for pneumonia.
  
  
• Taking supplements of folic acid. Bone marrow requires folic acid for the production of red blood cells. People with sickle cell anemia may benefit from taking folic acid supplements daily to boost their red blood cell production.
  
  
• Eating a well-balanced diet. Good nutrition can provide the body with the vitamins needed to produce red blood cells.
  
  
• Drinking plenty of water. Drinking water allows patients to stay hydrated. This maintains dilution of the blood, which reduces the likelihood that sickle cells will form.
  
  
• Avoiding extreme temperatures. Patients with sickle cell anemia should avoid exposure to extreme cold or heat because such temperatures may cause sickle cells to form.
  
  
• Limiting exposure to the sun. Too much solar exposure can cause dehydration, a condition that increases the likelihood that sickle cells will form.
  
  
• Avoiding and reducing stress. Patients should avoid stress because it can cause tissue deoxygenation and trigger a sickle crisis. Stress related to living with a chronic, life-threatening disease may be reduced by attending counseling and support groups. These outlets may help the patient relieve stress by sharing common experiences.
  
  
• Exercising regularly. People with sickle cell anemia may benefit from moderate exercise. Patients should discuss exercise with their physician prior to starting as excessive exercise can be harmful. Strenuous exercise, particularly when the spleen is enlarged, can deprive the tissues of oxygen (cause deoxygenation). Low oxygen levels may lead to a crisis. A crisis may also be triggered by dehydration, overheating or exhaustion caused by overactivity.  Also, individuals with an enlarged spleen should not engage in contact sports or activities that could rupture the spleen.
  
  
• Avoiding environments low in oxygen content. Environments with low oxygen content can lead to tissue deoxygenation and cause a crisis. To avoid complications, patients should avoid high altitudes and fly only on airplanes with pressurized cabins. They should also avoid spending long periods of time under water.
  
  
• Getting plenty of rest and sleep. Lack of sleep and rest can lead to the development of a sickle cell crisis.
  
  
• Avoiding use of alcohol, tobacco and illegal drugs. Patients should avoid these substances because use can trigger a sickle cell crisis.
  
  
• Seeing a physician regularly. People with sickle cell anemia require regular healthcare visits. During these visits, physicians will measure the patient’s red blood cell count and monitor the patient’s general health. The physician will determine whether the patient is getting enough nutrition and physical activity. In many cases, individuals must be monitored by a hematologist (physician who specializes in blood disorders) or internist (physician who specializes in internal organs). Because sickle cell anemia can cause damage to the eyes, patients should also schedule regular visits to an ophthalmologist. Regular dental exams are also important to prevent infection and tooth loss.
  
  Physician visits are particularly important for children with the disease. The National Heart, Lung and Blood Institute recommends that children under the age of 2 visit their physician every two or three months. After the age of 2, children should be scheduled for an appointment at least every six months. This will enable the physician to check the growth of the child and ensure that the young patient receives all of the vaccinations required. 
  
  
• Learning about the disease. Patients can benefit from learning about sickle cell anemia. Learning the signs of complications enables patients to seek early treatment when necessary. For example, patients can prevent serious infection by contacting their physician at the first sign of an illness.

Couples in which both partners carry the sickle cell gene may be able to lower their risk of having a child with sickle cell anemia.

During a procedure known as preimplantation genetic diagnosis, eggs are collected from a woman and sperm is taken from the male partner. The sperm is used to fertilize the eggs in a laboratory. Tests are then used to determine which eggs contain the sickle cell gene. Eggs that are found to be free of the defective gene are then implanted into the woman for development.

Although this form of in vitro fertilization improves a couple’s chances of having a child with normal hemoglobin, the procedure is not always successful. In addition, the cost of the procedure can be high.

In couples who carry the sickle cell gene, there is no way to reduce the risk of having a child with sickle cell anemia through normal conception. These individuals are encouraged to receive genetic counseling to thoroughly understand the risks involved with having children.

There is a great deal of research being conducted into sickle cell anemia, including clinical trials and scientific studies. Many studies focus on developing more effective treatment methods. Areas of research include:

• Gene therapy. Researchers are studying the idea that correcting the defective gene that causes sickle cell anemia and placing it into the bone marrow of people with the disease will result in production of normal hemoglobin. Additional studies are focusing on the possibility of deactivating the defective gene while reactivating the gene responsible for producing fetal hemoglobin.  
  
  
• Butyric acid. Butyric acid is a commonly used food additive. Researchers are investigating the possibility that the substance may increase the quantity of fetal hemoglobin in the blood.
  
  
• Clotrimazole. Clotrimazole is an over-the-counter drug commonly used to treat fungal infections. Researchers are studying the drug to determine if it can reduce the number of sickle cells that form by preventing the loss of water from the red blood cells.  
  
  
• Nitric oxide. Nitric oxide is a gas that keeps the blood vessels open and reduces the adhesiveness of red blood cells. Researchers are investigating whether treatment with this gas would prevent the formation of sickle cells.
  
  
• Hydroxyurea. Although the drug has been approved for the treatment of sickle cell anemia in adults, researchers are still in the process of determining proper dosage for children.
  
  
• Blood transfusions. Repeated blood transfusions can trigger iron overload, a disorder that can cause organ damage. Researchers are trying to develop new methods of eliminating the accumulation of iron in the body.

Preparing questions in advance can help patients and parents to have more meaningful discussions with their physicians regarding their or their child’s treatment options. The following questions related to sickle cell anemia may be helpful:

1. Could my pain be due to sickle cell anemia?
   
   
2. What else might be causing my symptoms?
   
   
3. What tests for sickle cell anemia will I undergo, and what do they involve?
   
   
4. How can I determine if I am a carrier?
   
   
5. What do my test results show?
   
   
6. What are my treatment options, and which do you recommend?
   
   
7. Am I at high risk of a stroke? If so, will I need regular blood transfusions?
   
   
8. What other complications of sickle cell anemia might I experience?
   
   
9. How can I prevent these complications?
   
   
10. What are the odds that my children will be born with sickle cell anemia?
    
    
11. Can I prevent passing the gene on to my child?
    
    
12. How can genetic counseling help us in family planning?
    
    
13. Is a cure for sickle cell anemia on the horizon?