Sickle cell disease (SCD) is a group of blood disorders that affect how red blood cells work. Misshapen red blood cells can become stuck in small blood vessels and block blood and oxygen flow to vital tissues and organs. This can lead to various health complications throughout the body.

Healthy red blood cells are round and pliable, but in people with SCD, they are crescent-shaped and stiff.

The complications of SCD can range from mild to life threatening. People with the disease can have pain episodes and problems with organ function, as well an increased risk of infections and stroke.

Read on to learn more about the complications of sickle cell disease, including how to prevent and treat them.

The following is a list of some of the complications that doctors associate with SCD.

Vaso-occlusive crisis (VOC)

This is the most common complication of SCD.

VOC happens because the misshapen red blood cells can become stuck in the small blood vessels. As a result, they form clots that restrict blood flow and oxygen supply to the tissues. This damages the blood vessels and causes inflammation.

When the blood flow returns to the area, it can intensify the inflammation, causing extreme and debilitating pain.

Although it can happen in any part of the body, it typically occurs in the long bones of the arms and legs and in the spine, pelvis, chest, and abdomen. The resulting pain and swelling can also affect the hands and feet.

The symptoms may begin in the first few months of life.

Acute chest syndrome (ACS)

ACS happens when clumps of sickle cells form in the lungs. Doctors can see these blockages on chest X-rays.

A person may experience fever, chest pain, and respiratory symptoms, including:

ACS can progress to hypoxemia or low blood oxygen. Without treatment, it can even result in respiratory failure. ACS is the most common cause of death in people with SCD.

People with SCD and asthma are two to four times more likely to experience ACS than those with SCD alone.


People with SCD may develop anemia. This condition occurs when the body does not have enough healthy red blood cells to carry oxygen to the tissues. People may experience the following:

Learn more about sickle cell anemia.


People with SCD have an increased risk of infections because their spleen does not work as it should. They may be more prone, for instance, to the flu, meningitis, and pneumonia.

The spleen makes up part of the immune system and acts as a filter in the body. Sickle cells can become stuck in the spleen, which can cause damage and scarring.

The symptoms depend on the location of the infections, but they may include fever and pain.

Children with SCD must receive vaccinations for the following:

Splenic sequestration

In some people with SCD, the spleen becomes blocked by the buildup of sickle cells within it. As the spleen fills with blood, it enlarges, and the anemia becomes more pronounced. This is known as splenic sequestration.

This condition can lead to swelling of the spleen. The most common symptom is pain on the left side of the abdomen.

Splenic sequestration commonly affects children. Parents and caregivers should monitor children with SCD and seek medical attention if they experience severe pain in the abdomen or swelling of the spleen.

Pulmonary hypertension

Pulmonary hypertension is a type of high blood pressure that affects the arteries in the lungs and the right side of the heart.

It can occur in up to 10% of people with SCD and carries a mortality rate of 2–5%.

At first, the symptoms of pulmonary hypertension may include only vague symptoms, such as difficulty breathing and fatigue.

As the condition progresses, an individual may experience the following symptoms:


Stroke occurs due to a reduction in the blood supply to part of the brain. It is a medical emergency that can cause paralysis, vision problems, and confusion.

Approximately 11% of people with SCD have a stroke by the age of 20 years. It can affect children as young as 2 years of age.

However, silent cerebral infarcts (SCI) are more common than overt strokes. With SCI, individuals may experience no symptoms, but doctors can see the signs on imaging tests.

Pulmonary embolism (PE)

People with SCD have an increased risk of developing blood clots, such as deep vein thrombosis (DVT) and PE.

PE happens when a blood clot becomes lodged in the pulmonary artery or one of its branches and blocks the blood flow to the lungs. It can cause shortness of breath, chest pain, lung damage, and death.

The incidence of PE is higher among people with SCD than among those who do not have the disease.

People with SCD should seek urgent medical attention if they have symptoms of PE.

Renal complications

Renal, or kidney, complications are very common in people with SCD. About 30% of people develop chronic renal failure.

Sickle cells may cause a reduced blood flow to the kidney, which can lead to damage or chronic disease. The kidneys are responsible for filtering waste from the blood and making urine. The symptoms of kidney dysfunction include:

Eye complications

People with SCD may experience vision loss due to reduced blood flow to the vessels in the eye. Most commonly, this occurs in the retina, which is responsible for sending images to the brain.

The blockage may not always cause symptoms initially, but it can suddenly progress.

Liver complications

Some people with SCD may experience cholelithiasis. This condition occurs when gallstones — hard, rock-like structures — form in the gallbladder.

The breakdown of sickle cells occurs at a much faster rate than that of healthy red blood cells. This can lead to the excessive production of a waste product called bilirubin. Excess bilirubin may cause gallstones to develop. People may experience the following symptoms:

Avascular necrosis (AVN)

AVN commonly affects the hip joint.

In people with SCD, the sickle cells may block blood flow to the bones. When the bone tissue does not receive enough oxygen, it can die.

Also, when the amount of blood reaching the bone is insufficient, the joints begin to narrow and may cause the bone to collapse. Symptoms may not appear initially, but as the disease progresses, people typically experience joint pain.

The type of complication will determine the treatment options. For example, VOC management involves pain relieving medications and hydration until the individual experiences relief from the symptoms.

Doctors may recommend acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs) for mild pain, but for moderate and severe pain, they may prescribe opioids.

If the individual has a fever, doctors should assess them for life threatening infections. They may order a complete blood count, blood culture, and urine culture. If a bacterial infection is present, the doctor will likely prescribe antibiotics.

For complications such as ACS, the individual may require:

  • supportive care of oxygen and fluids
  • blood transfusions
  • antibiotics, such as penicillins, cephalosporins, and macrolides
  • pain relievers

Pregnant people with SCD are more likely to have problems during pregnancy that could affect their own health or that of the baby.

For example, they may find that their SCD becomes more severe, causing more frequent episodes of pain.

They also have an increased risk of preterm labor and giving birth to a baby with low birth weight.

However, with early and comprehensive prenatal care and careful, frequent monitoring throughout pregnancy, a person with SCD can have a healthy pregnancy.

It may not be possible to prevent complications in all cases. However, people with SCD can take steps to stay healthy. Examples include:

  • Practicing good hygiene: Hand washing after using the bathroom and before eating can help prevent illness and infection.
  • Getting vaccinated: Children and adults with SCD should have all the recommended vaccinations. They may also receive pneumococcal, meningococcal, and HiB shots.
  • Following food safety guidelines: It is important to cook meats and eggs thoroughly before eating them. People should also avoid consuming unpasteurized milk and dairy products. Experts recommend washing the hands before touching and preparing food.

Additionally, people should find good medical care, if possible, and have regular checkups to help prevent serious complications.

The complications of sickle cell disease can range from mild to life threatening. Although some may not cause serious issues besides discomfort, others, such as stroke, can be dangerous.

People can help prevent complications by practicing good hygiene, receiving vaccinations, following food safety guidelines, and having regular health checkups.