Sickle Cell Anemia: Causes, Symptoms, Diagnosis, and Treatment

Key takeaways:

• Sickle cell anemia is a genetic condition caused by inheriting two sickle cell genes, leading to abnormal hemoglobin.
• Symptoms of sickle cell include severe pain episodes, anemia, fatigue, swelling in hands and feet, frequent infections, delayed growth, vision problems, and organ damage.
• It can be diagnosed through newborn screening, blood tests like hemoglobin electrophoresis, and genetic testing.
• Sickle cell can be managed with medications like hydroxyurea, blood transfusions, pain relief, and lifestyle changes.
• Staying hydrated, avoiding extreme temperatures, managing stress, and regular checkups help prevent SCD complications.

Sickle cell anemia is a severe form of sickle cell disease that presents with anemia. Anemia is when you do not have sufficient healthy red blood cells to carry oxygen from the lungs to various organs and tissues.

Sickle cell disease (SCD) is a group of inherited blood disorders that change the shape and function of red blood cells. Red blood cells, also called erythrocytes, are important components of the blood that contain hemoglobin, a protein that carries oxygen through the blood.

Normally, red blood cells are round and flexible, allowing them to flow easily through blood vessels. But in people with SCD, these cells become stiff and curved like a crescent or sickle in the presence of reduced oxygen levels.

Because of repeated sickling and unsickling, the red blood cells become stiff and lose their normal flexible shape. This makes it hard for them to squeeze through tiny blood vessels, causing blockages that can lead to pain, organ damage, and other problems.

These damaged cells also die much faster than normal—lasting only about 10–20 days instead of the usual 120—leading to a constant shortage of red blood cells, known as anemia. 

Sickle cell disease is most common in areas where malaria is or was widespread, including sub-Saharan Africa, parts of the Middle East, India, and the Mediterranean.

In the United States and other Western countries, it mainly affects people of African, Hispanic, and Mediterranean backgrounds. Millions of people around the world live with SCD, and in the U.S., about 100,000 individuals are affected.

What causes sickle cell anemia?

Sickle cell anemia occurs due to a mutation in the Beta chain of hemoglobin, which is responsible for producing hemoglobin, the protein in red blood cells that transports oxygen.

This mutation results in the formation of an abnormal type of hemoglobin known as hemoglobin S, replacing the normal hemoglobin A.

How it happens:

This explains how the person comes about to be a sickle cell patient.

1. Genetic inheritance: Sickle cell anemia is passed down in an autosomal recessive manner, which means a person must receive two defective gene copies (one from each parent) to have the disease (SS). If they inherit only one copy (AS), they will have sickle cell trait but not the full condition.
2. Abnormal hemoglobin production: Hemoglobin S makes red blood cells rigid and forces them to take on a sickle or crescent shape rather than their usual round form.
3. Blocked blood flow: The crescent-shaped cells stick together and obstruct small blood vessels, limiting oxygen supply to organs and tissues.
4. Rapid cell breakdown: These misshapen red blood cells break down more quickly than normal ones, leading to anemia (a lack of healthy red blood cells) and reduced oxygen supply, which can cause fatigue, weakness, and other health issues.

While the main cause is genetic, factors like dehydration, infections, and stress can worsen symptoms by increasing the likelihood of red blood cells sickling.

Risk factors for sickle cell anemia

Some factors can increase the chances of having sickle cell anemia. These include:

• Genetic inheritance – The disease is passed down from parents. A person must get two copies of the sickle cell gene (one from each parent) to have the disease. If they get only one copy, they will have sickle cell trait but not the full illness.
• Geographic regions – People from areas where malaria is or was common have a higher chance of carrying the sickle cell gene, as the trait offers some protection against malaria.
• Ethnic background – Sickle cell anemia is more common among people of: Africa (especially sub-Saharan Africa), India and South Asia, the Middle East, the Mediterranean (Greece, Italy, Turkey), Hispanic and Caribbean communities.

Symptoms of sickle cell anemia

The symptoms of sickle cell anemia can vary from person to person and may change over time. Some symptoms appear early in childhood, while others develop later. Common symptoms include:

• Sudden episodes of severe pain, often in the chest, joints, back, and limbs (pain crises)
• Feeling tired, weak, or dizzy due to a lack of healthy red blood cells (anemia)
• Swelling in the hands and feet, especially in babies
• Getting sick more often because the body has a weaker defense against infections
• Slower growth and delayed puberty in children and teenagers
• Vision problems, including blurry eyesight or possible vision loss
• Shortness of breath and chest pain which can be serious

These symptoms may get worse with stress, dehydration, extreme temperatures, or illness.

Diagnosis of sickle cell anemia

There are methods of knowing if a person is a sickle cell patient or if the person is just a carrier. These include:

1. Blood test (hemoglobin electrophoresis)

Doctors may carry out a blood test for sickle hemoglobin (HbS) to confirm if a person has sickle cell disease or just carries the trait.

2. Newborn screening

Newborn screening, often called the heel prick test, uses a small blood sample to check for conditions like sickle cell disease. In countries like the U.S., the test—known as the Guthrie test—is routine, but it may not be widely practiced in sub-Saharan Africa.

3. Complete blood count (CBC)

The complete blood count test measures red blood cell levels to check for anemia.

4. Blood smear test

During a blood smear test for sickle cell anemia, a microscope is used to look at red blood cells; sickle-shaped cells confirm the disease.

5. Genetic testing

A genetic test can find changes in the HBB gene to confirm if someone has sickle cell disease or is a carrier.

6. Other tests

Doctors may also check oxygen levels, heart, brain, and kidney function to detect complications.

Management and treatment

Sickle cell can be managed with medications, surgery and lifestyle modifications.

Medications

These medications help to manage the symptoms of sickle cell:

• Hydroxyurea: This drug reduces the frequency of pain episodes, decreases the need for blood transfusions, and boosts the production of healthy red blood cells.
• Pain medications: Pain medications help control pain, ranging from mild discomfort to severe crises, such as NSAIDs (Non-steroidal anti-inflammatory drugs)
• Antibiotics & vaccines: These drugs help prevent infections since people with sickle cell disease have a weaker immune system. Malaria chemoprevention is also essential, especially in endemic regions, since malaria can trigger severe complications in SCD patients.
• Supplements: People diagnosed with sickle cell disease (SCD) are commonly prescribed supplements like folic acid to support red blood cell production, as their bodies break down cells faster than normal.

Malaria chemoprevention is also essential, especially in endemic regions, since malaria can trigger severe complications in SCD patients.

Advanced treatment options

Aside from the management options, there are methods aimed at treating sickle cell, including:

• Blood transfusions: A blood transfusion may be carried out if you have sickle cell anemia to replace abnormal sickle-shaped red blood cells with normal ones to help prevent complications like anemia and strokes.
• Bone marrow or stem cell transplant: Bone marrow or stem cell transplant offers the only possible cure for sickle cell anemia. However, this procedure needs a suitable donor and is not easily accessible for everyone.
• Gene therapy (still being studied): Researchers are exploring ways to change genes to find a permanent cure for sickle cell disease.

Lifestyle modifications

These steps will help people with sickle cell manage their symptoms and also reduce the occurrence of crises.

• Drinking plenty of water to prevent dehydration, which can trigger sickling
• Eating iron-rich and nutritious foods supports overall health
• Avoiding exposure to extreme weather conditions
• Reducing stress to help prevent pain crises
• Monitoring organ function and blood levels, which can help prevent complications

Complications of sickle cell anemia

Sickle cell anemia can lead to various complications due to the abnormal shape and function of red blood cells. Here are the key complications:

• Severe pain episodes due to blocked blood flow, commonly in the chest, back, arms, and legs
• Chronic anemia causing fatigue, weakness, and shortness of breath
• Increased risk of stroke, leading to sudden weakness, speech difficulties, vision problems, or loss of consciousness
• Acute chest syndrome, a serious lung complication with fever, chest pain, breathing difficulties, and low oxygen levels
• Organ damage affecting the liver, kidneys, heart, spleen, and eyes due to poor circulation
• Higher susceptibility to infections, including pneumonia and meningitis, due to impaired spleen function
• Vision problems caused by reduced blood flow to the retina, potentially leading to blindness
• Development of slow-healing leg ulcers as a result of poor circulation
• Gallstones form due to the excessive breakdown of red blood cells, leading to digestive discomfort
• Painful, prolonged erections in males (priapism) can cause long-term damage
• Too much iron can build up in the body due to frequent blood transfusions and the constant breakdown of red blood cells

Living with sickle cell anemia

With better medical care, people with sickle cell anemia are living longer, often into their 50s, 60s, or beyond. Early diagnosis, regular checkups, and proper management can greatly improve both health and quality of life.

Taking steps to prevent complications is key. Drinking plenty of water, eating a healthy diet, avoiding extreme temperatures, and managing pain can help reduce sickle cell crises.

Vaccinations and regular screenings are important to prevent infections and organ damage. Treatments like hydroxyurea and blood transfusions can also help manage symptoms.

A healthy lifestyle makes a big difference. Light exercise improves circulation, while stress management and good sleep help prevent crises. Emotional support from loved ones and patient groups can also make coping easier.

Wrap up

Sickle cell anemia is a lifelong condition, but it doesn’t have to limit a person’s potential. With proper care and a positive mindset, individuals can lead fulfilling lives, build careers, and achieve their goals. New treatments continue to bring hope for a better future.