Search

Complications

There are a variety of complications1 typically associated with sickle cell disease. Some complications are more severe than others and require immediate medical attention.  

Download the Children’s Healthcare of Atlanta Sickle Cell Disease Handbook for Patients and Families (English | Spanish)2 

Indicators of an Emergency

Anemia

Severe anemia requires medical attention. The symptoms of severe anemia are fatigue, shortness of breath, dizziness, and irregular heartbeat.

Stroke

People with SCD are at higher risk for having a stroke. Call 9-1-1 for any of these warning signs of a stroke: sudden weakness, numbness on one side of the body, confusion, or trouble speaking, seeing, or walking.

Fever

A temperature of 101°F or higher is considered a fever. It is often a sign of an infection and requires immediate medical attention. Other symptoms might include cough, chills, aches, tiredness, headache, vomiting, or diarrhea.

Acute Chest Syndrome (ACS)

ACS occurs when sickled cells clump together in the lungs and can become life-threatening if not treated right away. Symptoms include trouble breathing, fever of 101°F or higher, couch, chest pain, low oxygen level, and back/low belly pain.

Acute Chest Syndrome (ACS)

Download educational handouts here (English | Spanish) 

Acute chest syndrome (ACS) is a lung problem that happens in people who have sickle cell disease. It looks like pneumonia on a chest X-ray. It can be caused by 1 or more of these: 

  • Sickle red blood cells blocking blood vessels in the lungs, like a sickle cell crisis 
  • An infection in the lung 
  • Fat droplets in the lungs caused from a sickle cell bone pain or crisis 
  • Blood clots in the lung 
  • Extreme sleepiness from medicine being used to treat pain 

  

ACS can get worse quickly and become life-threatening. If you or someone you know with SCD experiences any of the symptoms below, get medical help right away. Call your sickle cell disease Clinic and head to the emergency department (ED). 

  

Symptoms:  

  • Trouble breathing (fast or heavy breathing) 
  • Fever or temperature of 101°F or higher 
  • Cough 
  • Chest pain 
  • A low oxygen level 
  • Back pain or belly pain 

Anemia

Most people with sickle cell disease have some anemia (low red blood cell count or low hemoglobin). This means the body has fewer red blood cells to carry oxygen. Anemia can make a person feel tired when they exercise or do physical work. The anemia may become worse with infection or other illnesses. 

Symptoms:  

  • Pale lips, gums or nails 
  • Weakness 
  • Feeling more tired than normal 
  • Sleeping longer 
  • Headache 
  • Not eating or drinking as much as normal 
  • Irritability 

 

Call the Sickle Cell Disease Clinic right away if you or someone you know with SCD experiences these symptoms and be prepared to head to the hospital or clinic. A person with SCD with these symptoms needs their hemoglobin level checked and may need a blood transfusion if the hemoglobin level is too low. Transfusion helps deliver oxygen to the body so it can keep working well. 

Aplastic Crisis

Download educational handouts here (English | Spanish) 

Aplastic crisis happens when the body stops making red blood cells (RBCs) for a short time. This causes a drop in a person’s hemoglobin level (red blood count) for a short time. For people living with sickle cell disease, many RBCs are broken down each day. This means that many more RBCs need to be made each day. 

  • Infections may cause the bone marrow to stop making RBCs for a few days. Most often, this is not a problem for people who do not have sickle cell disease. 
  • For people with sickle cell disease, severe anemia (very low hemoglobin) can happen if the bone marrow stops making RBCs, even for a few days. 
  • A person with SCD may need a blood transfusion if the hemoglobin level is too low. A transfusion helps deliver oxygen to the body so it can keep working well. 

 

Several types of infections can prevent bone marrow from making RBCs. Most happen when children are old enough to go to school.  

Symptoms: 

Many of the symptoms come from a low RBC count. This may include: 

  • Pale lips, gums or nails. 
  • Feeling weak all over. 
  • Feeling very tired or sleepy. 
  • Fever or a recent fever (temperature of 101°F or higher). 
  • Fast heartbeat. 
  • Headache. 
  • Feeling short of breath. 
  • Being cranky. 

Avascular Necrosis (bone changes)

Download educational handouts here (English | Spanish) 

Avascular necrosis (AVN) is a well-known complication of sickle cell disease that affects up to 10% of people with sickle cell disease and can happen with all sickle cell types. AVN is a type of bone damage that most often starts during the teen years and becomes more common with age. It is caused by a lack of blood supply to the bone.   

Symptoms:  

Many people with early AVN may not have any symptoms. As AVN gets worse, they may experience some or all of these symptoms: 

  • Pain, tenderness and soreness in the shoulders, groin, knee, and buttocks. 
  • Pain that is sharp, dull or aching 
      • It may be different than a regular pain episode. 
      • It could worsen by putting weight on the area involved (weight bearing) or moving (such as walking, climbing stairs or sitting for long periods of time). 
  • Stiffness or tightness in the involved joint 
      • AVN can feel like arthritis pain. 
      • The person may walk with a limp. 
      • There may be less movement of the joint that is in pain. 

Jaundice and Gallstones

Download educational handouts here (English | Spanish) 

 

What is jaundice?  

Jaundice is when the white part of the eye and skin turn yellow.  

  • Bilirubin is a yellow substance that is is made from the hemoglobin that is released when RBCs break apart. 
  • When fragile, sickle red blood cells break open and bilirubin leaks out into the blood stream. 
  • As blood travels throughout the body, bilirubin pigment causes the eyes and skin to turn yellow (jaundice).  

 

What are gallstones?  

The gallbladder is a sack or pouch under the liver. It is in the upper right part of the belly. Gallstones are small stones that form in the gallbladder when bile hardens into a solid form. 

  • Bile is most often a liquid and is used to help break down (digest) fats that we eat.  
  • Bile is made by the liver and stored in the gallbladder.  
  • People with sickle cell disease make more bile that forms a thick sludge and causes stones to form (gallstones).  

 

Gallstones are most often not harmful. If they get stuck in the tube that leaves the gallbladder, pain may occur. Infection can occur if the tube gets blocked by stones. This can affect other organs nearby, like the pancreas. 

 

Symptoms:  

  • A yellow color of the skin or whites of the eyes  
  • Sudden, sharp belly pain mostly on the right, upper part of the belly. The pain may get worse after eating fatty foods.  
  • Upset stomach or vomiting (throwing up) 
  • Fever (temperature higher than 101°F) 
  • Pale color of the lips, gums or nails  
  • Weakness  
  • More tired than normal  

Fever and Infection

Fever or infection can be an emergency. Seek medical attention right away! 

Download educational handouts here (English | Spanish) 

A person has a fever if their temperature is 101°F or higher. It is often the first sign of an infection, and it is important to pay attention to temperature measurement in order to treat infections quickly. 

An infection happens when germs (bacteria or viruses) are not recognized by the body. These germs continue to grow and spread. This causes an infection. Infections are a big danger to people with sickle cell disease. People living with SCD have a higher chance of getting certain infections than those who do not have sickle cell disease and can die from infections caused by bacteria if not treated quickly. Usual childhood viral infections, such as common cold or strep throat, are not more common but can cause sickle complications. 

Additional Symptoms: 

  • Cough 
  • Chills 
  • Cold symptoms like a stuffy or runny nose 
  • Body aches 
  • Not want to eat or participate in regular activities 
  • Feeling weak or tired (fatigue) 
  • Headache 
  • Vomiting (throwing up) or diarrhea (loose stools) 
 

Preventing Infection:  

  • Take penicillin daily for the first few years of life. 
  • Get immunizations (vaccines) and keep them updated to help protect the body from harmful germs. 
  • Clean your hands often. Wash them well with soap and water for at least 20 seconds or use an alcohol-based gel or foam.  

Hepatic Sequestration (liver problems)

Hepatic sequestration happens when red blood cells get trapped inside the liver instead of the blood. It requires immediate medical attention, so call your Sickle Cell Disease Clinic or go to the nearest emergency department (ED) right away if you or someone you know with sickle cell disease experiences any of the symptoms.  

Symptoms: 

  • Pale skin color 
  • Belly pain 
  • Yellowing of the eyes (jaundice) 
  • Nausea (upset stomach) and vomiting (throwing up) 

Iron Overload

Download educational handouts here (English | Spanish) 

Iron overload means the body has stored more iron than it needs. While everyone needs iron for the body to function properly, it can cause health problems when too much iron builds up to a level that overloads the body. 

  

Blood transfusions are used to treat many different types of sickle cell problems. People who receive blood transfusions over a long period of time can have a buildup of extra iron. 

  • Each unit or pint of blood contains a lot of iron. 
  • The body can only store a small amount of iron safely. 
  • The body does not have a natural way to get rid of the extra iron. 
  • The extra iron builds up in the body over time. 
  • It is stored in major organs like the liver and heart. 
  • The body cannot function like it should with extra iron. 

  

People who receive frequent blood transfusions will have their iron levels checked regularly. It is important to treat high iron levels because the extra iron will cause organ damage. Iron stores itself on the liver, heart, skin, pancreas, and reproductive organs (ovaries in girls, testes in boys). 

 

Symptoms:   

  • Weight loss 
  • Fatigue (feeling very tired) 
  • Bronze or gray skin 
  • Joint pain 
  • Shortness of breath 
  • Swelling of ankles 
  • Abdominal (belly) swelling or pain 
  • Blood in the stool 
  • Stunted growth 
  • Delayed puberty 
  • Diabetes (increased thirst and increased urinating) 

Kidney Problems

Sickle cell disease can also affect the kidneys. Kidney problems can start early in life and get worse over time. Sickle cell nephropathy happens when there is damage to parts of the kidney. 

  • The kidneys are filters for the blood. They make urine, which allows your body to remove salts, waste and extra water from your blood. They also help your body to keep the important parts of your blood like proteins and cells inside the blood. 
  • In sickle cell nephropathy, parts of the kidney are damaged by sickle cells. This does not cause pain. You may not know there is any damage to the kidneys unless it is found in blood or urine tests. 
  • Sickle cell nephropathy happens very slowly. If it starts in childhood, it may slowly cause more damage over several years and become more severe in teens and adults. 

  

When the kidneys are damaged by sickle cells: 

  • Small amounts of protein in the blood can leak out of the blood and be lost in the urine. One of these proteins is called albumin. Having too much protein in urine is called proteinuria or albuminuria. This is an early sign that kidney damage has started. 
  • Blood can sometimes appear in the urine when the kidneys are damaged. This is called hematuria. The bleeding can last for a few hours or a few days. Seek medical attention right away for blood in the urine.  
  • As damage to the kidneys gets worse over years, the kidneys may stop working (kidney failure). A person with kidney failure may not be able to make urine. People with kidney failure need dialysis (a machine to help the body get rid of waste) a few times each week to survive. They may also need a kidney transplant if the condition is not improved with dialysis. 

 

To help prevent kidney damage: 

  • Drink plenty of fluids each day. 
  • Know what your normal blood pressure is and when the numbers may be too high. 
  • Avoid medicines that can harm the kidneys. This includes over-the-counter medicines. 

Leg Ulcers

Download educational handout here3  Often when people with sickle cell disease get older, they can develop painful leg ulcers. Poor circulation of blood in the leg can lead to ulcers that typically show up on the lower part of the leg. Leg ulcers happen more often in males than in females. They usually appear in people aged 10 to 50 years.4 A combination of factors can cause ulcers, including: 
  • Trauma 
  • Infection 
  • Inflammation (swelling) 
  • Poor blood flow in the smallest blood vessels of the legs 
Symptoms: 
  • Open sores 
  • Pain in the affected area 
  • Pus or discharge in the affected area 
  • Swelling 
  • An itchy or burning feeling 

Pain

Pain causes significant concerns for those living with sickle cell disease and can manifest in a variety of ways.  

Pain Episodes (Acute Pain)

Download educational handouts here (English | Spanish) 

Pain is one of the most common symptoms of having SCD.  Pain and other sickle cell problems happen when the red blood cells (RBCs) become sickle shaped. The sickle-shaped cells are sticky and clump together. These clusters of sickle cells block blood flow and oxygen to parts of the body. This can cause pain to the affected area. 

  

A pain episode (also called a vaso-occlusive episode) is the most common problem for people with sickle cell disease. A pain episode can happen anywhere in the body because blood flows everywhere. Some of the more common areas are the bones, lungs, spleen, brain, eyes and kidneys. 

  • When tissue is damaged, the injury causes nearby nerves to send electrical signals to the brain. The signals are felt as pain. 
  • Pain can continue for some time until the tissues start to heal and the nerves calm down. 
  • In some individuals, pain can last longer because the nerves do not calm down. 

  

Symptoms: 

Everybody feels pain in a different way, so the symptoms can vary from person to person. Pain episodes can happen: 

  • Suddenly and without warning. 
  • With some warning signs. 
  • With other sickle cell problems, mainly in the lungs. 
  • As a result of another sickle cell problem, such as gallstones. 

  

Sometimes people can have pain for a short period of time. This type of pain is called acute. It can last anywhere from a few hours to a few weeks. There are other individuals who have pain that stays all the time. This pain is called chronic. Acute pain and chronic pain have different treatments.  

 

Prevention: 

It is not fully understood what causes a person to have a pain episode. For that reason, it is hard to find ways to prevent them. People have their own triggers or patterns with pain. Some things that seem to play a role include: 

 

  • Physical and mental stress. 
  • Changes in the weather. 
  • Being very tired. 
  • Dehydration. 
  • Infections. 
  • For some older girls and women, pain episodes happen around their monthly period. 

  

  

Healthy lifestyle habits can help prevent some pain. Some of these habits include:  

  • Drinking enough water. 
  • Sleeping 7 to 8 hours each night. 
  • Reducing or treating stress. 
  • Avoiding cold water directly on the skin or ice packs. 
  • Being on a disease-modifying medication like hydroxyurea 

Chronic Pain

As a person gets older, sickle cell disease pain can become chronic (long-term). 

  • When tissue damage happens, nearby nerves send signals to the brain that are felt as pain. 
  • Some people have pain every day. 
  • Chronic pain is treated both at home and in the hospital. 

 

 Chronic pain is treated in a different way than acute (short-term) pain and usually includes a treatment plan. This plan may include: 

  • Regular and frequent visits with a sickle cell disease provider.  
  • Anti-inflammatory medicine. 
  • Muscle relaxers. 
  • Meeting with a pain specialist. 
  • Visits with a psychologist. 
  • Physical therapy (PT) and TENS units (Transcutaneous Electrical Nerve Stimulation), battery-powered devices that deliver low-voltage electrical currents to the skin to relieve pain. 
  • Strong, long-acting pain medicines taken by mouth (swallowed). 
  • I.V. fluids and I.V. anti-inflammatory medicines in the hospital or clinic. 

Priapism

Download educational handout here5 

Priapism is a long-lasting, unwanted, painful erection (firmness) of the penis. 

  • It results from sickle cells blocking the blood vessels in the penis. 
  • Priapism can happen as early as age 5, but more often affects older boys and men. 
  • It often happens late at night or early in the morning. 

 

If there are multiple, shorter episodes of painful erections (lasting less than four hours), this is called stuttering priapism. It’s important to talk to an SCD provider if you experience stuttering priapism and to tell them about the frequency of the episodes.  

Priapism is very uncomfortable and needs treatment right away.  If priapism lasts longer than 2 hours, call your Sickle Cell Disease Clinic right away or go to the nearest emergency department (ED). If not treated, priapism can lead to problems with sexual function or fertility problems later in life (difficulty having children). 

Learn more about priapism here:  

Pulmonary Hypertension (lung problems)

Pulmonary hypertension can happen in people with sickle cell disease. It is caused by increased blood pressure in the blood vessels that carry blood from the heart to the lungs. 

  • The high pressure can lead to narrow arteries (blood vessels). This can cause the heart to work harder as it pumps blood. 
  • It is most often found by doing an ultrasound of the heart (echocardiogram). 
  • It is more common in adults than children. 

  

Pulmonary hypertension can be caused by: 

  • The breakdown of an excess number of red blood cells (hemolysis). 
  • Having low oxygen levels for a long time. 
  • Repeated blockage of the blood vessels by sickle red blood cells and clots. 

 

Symptoms: 

Symptoms of pulmonary hypertension are also common in other conditions like asthma. They can be mild to severe and may include: 

  • Dizziness 
  • Trouble breathing 
  • Fatigue (feeling very tired) 
  • Chest pain 

Retinopathy (eye problems)

Download educational handouts here (English | Spanish) 

Retinopathy is damage to the retina in the eyes. The retina is the “seeing” part of the eye. It is in the back of the eye, contains nerves and small blood vessels, and captures light and images so we can see. 

 

Eye problems are more common in older children and adults with HbSC and HbS Beta + Thalassemia. This may be due to a higher hemoglobin level in patients with these types of sickle cell disease which makes the blood thicker. As this “thicker” blood travels through the small blood vessels in the eyes, it causes damage to these vessels and can lead to vision loss if not treated early. Early detection by annual eye examination by an eye doctor that understands sickle cell disease is important to prevent vision loss and other problems. 

 

Sickled red blood cells can get trapped inside the small blood vessels in the retina. This can cause: 

  • A decrease in blood flow. This can lead to damage of the retina. The damage may be permanent. 
  • Bleeding in the eye. 
  • When blood vessels get blocked, the eye makes new vessels to replace the blocked vessels. 
  • The new vessels are thinner and weaker. They may break open and bleed. 
  • The bleeding causes damage to the retina. Bleeding can also cause the retina to loosen from the rest of the eye. This is called a detached retina. Damage to the retina can cause changes in eyesight. If the damage is not treated, blindness may happen. 

  

Symptoms:  

At first, there may be no symptoms. This is why a yearly eye exam is very important for people living with sickle cell disease. When retinopathy worsens, some of these symptoms may appear: 

  • Flashes and dark shadows in some parts of the vision (floaters) 
  • Blurred vision 
  • Sudden loss of vision 
  • Pain in the eyes 

Splenic Sequestration (spleen problems)

Download educational handouts here (English | Spanish) 

Splenic sequestration occurs when sickled red blood cells block blood vessels inside the spleen, preventing blood from leaving the spleen and blocking circulation to other vital organs. This is one of the most common causes of death in children with sickle cell disease. 

  • With splenic sequestration crisis, the spleen suddenly gets swollen and big because the spleen is the first organ injured by sickle cells in the blood. The sickle red blood cells block the blood vessels inside the spleen. This prevents the blood from leaving the spleen. 
  • When this happens, a large amount of blood gets trapped in the spleen. This causes the spleen to get swollen. 
  • Since the blood cannot get back into the bloodstream, the hemoglobin level (RBC count) can go down to very low levels. 
  • There may not be enough blood left in the bloodstream for vital organs to work as they should. 
  • This can lead to shock and is a medical emergency. 
  • This is one of the most common causes of death in children with sickle cell disease. 

 

Symptoms: 

  • Enlarged (swollen) spleen 
  • Pale lips, gums or nails 
  • Fast breathing 
  • Fast heartbeat 
  • Weakness 
  • Pain in the area around the spleen, lower left chest, or left shoulder 
  • Feeling more tired than normal 
  • Not wanting to take part in normal activity 
  • Sleeping longer 
  • Not eating like normal 

Stroke

Download educational handouts here (English | Spanish) 

A stroke is the loss of blood supply to part of the brain. A stroke is caused when either a blood vessel in the brain is blocked or there is bleeding of the blood vessels inside the brain. Strokes are more likely to happen in people living with sickle cell disease because: 

  • Blood vessels can get blocked by sticky sickle red blood cells (RBCs). 
  • Sickle cells cause the blood vessels in the brain to become narrow. This makes it easier for the sickle cells to get stuck. 
  • Blood vessels damaged by sickle cells can bleed more easily. 

 

Stroke is an emergency that requires immediate medical attention. Transfusions can reverse strokes if given immediately and prevent future strokes if given on a regular schedule. A simple test called transcranial doppler (TCD) done every year can detect children at risk for stroke so transfusions can be started to prevent the first stroke. Strokes are more common with hemoglobin SS but can also happen in other types of sickle cell disease. They also happen more in children ages 2 to 5 years old but can happen at any age. 

 A stroke cuts off normal blood and oxygen supplies to part of the brain. This causes brain cells to die and brain damage to happen. The damaged part of the brain does not work like it should. The parts of the body the damaged brain area controls do not work well either. This is why an arm or leg can be weak or not able to move after a stroke. A stroke may also cause problems with memory and learning. 

 

Symptoms: 

  • Slurred or confused speech (when speech was clear before) 
  • Muscle weakness or unable to move 1 side of the body (face, arm or leg) 
  • Unsteady walk (when walking was normal before) 
  • Numbness or tingling of the arms or legs on 1 side of the body 
  • Very bad headache that does not go away 
  • Confusion 
  • Seizures (jerking or twitching of the face, arms or legs) 
  • Loss of consciousness (passing out) 
  • Changes in vision (seeing) 

Page Navigation

  1. Centers for Disease Control and Prevention. Complications of sickle cell disease. Centers for Disease Control and Prevention. https://www.cdc.gov/sickle-cell/complications/. 
  2. Children’s Healthcare of Atlanta. Sickle Cell Disease Handbook for Patients and Families. https://www.choa.org/-/media/Files/Childrens/teaching-sheets/sickle-cell-disease-handbook-for-patients-and-families.pdf 
  3. Legs Matter. Sickle cell and leg ulcers. Legsmatter.org. https://legsmatter.org/wp-content/uploads/2024/06/LEGS-MATTER-SICKLE-CELL.pdf. 
  4. Centers for Disease Control and Prevention. Complications of SCD: Leg ulcers. Centers for Disease Control and Prevention. https://www.cdc.gov/sickle-cell/complications/leg-ulcers.html. 
  5. Mayo Clinic. Priapism – symptoms & causes. https://www.mayoclinic.org/diseases-conditions/priapism/symptoms-causes/syc-20352005?p=1. 

Indicators of an Emergency Situation

Patients and families should watch for the following conditions that need an urgent medical evaluation:
• Fever of 101° F or higher
• Chest pain
• Shortness of breath
• Increasing tiredness
• Abdominal swelling
• Unusual headache
• Any sudden weakness or loss of feeling
• Pain that will not go away with home treatment
• Priapism (painful erection that will not go down)
• Sudden vision change

Learn more about sickle cell disease

Resources from:

Arise Initiative

ASH

CDC

NIH

SCDAA