Patient education: Sickle cell disease (The Basics)

What is sickle cell disease? — 

This is a condition that affects red blood cells, which carry oxygen to organs in the body.

Normally, red blood cells are shaped like half-filled water balloons. In sickle cell disease, a protein called hemoglobin does not form correctly. This causes some of the red blood cells to "sickle," which means they become stiff with sharp edges (figure 1).

The stiff cells can get stuck in blood vessels easily and cause blockages. When this happens, the red blood cells don't bring enough oxygen to the body's organs. This can cause severe pain and other medical problems.

What causes sickle cell disease? — 

Sickle cell disease is a lifelong condition a person is born with. It is caused by an change in 1 of the genes that makes a part of hemoglobin called "beta globin":

●If a person gets the sickle cell gene from both of their parents, they will have a form of sickle cell disease called "sickle cell anemia."

●If a person gets the sickle cell gene from 1 parent, and a different abnormal beta globin gene from the other parent, they will have another form of sickle cell disease. Examples of these different abnormal genes include "hemoglobin C" and "beta thalassemia."

●If a person gets the abnormal gene from only 1 parent, they will have "sickle cell trait." People with sickle cell trait generally do not have any of the symptoms of sickle cell disease. But they can pass the gene along to their children, and they do have a few small health risks. Sickle cell trait is common because it helps protect people from getting sick from malaria.

What are the symptoms of sickle cell disease? — 

Symptoms usually start after a baby is a few months old. Most commonly, people with sickle cell disease have episodes of pain. Some doctors call these a "sickle cell pain episode" or "sickle cell crisis." But do not wait for pain to become a crisis before you get help.

Sickle cell pain can happen in the bones, chest, or other parts of the body. It can be mild or severe, and last hours to days. People can have other symptoms, too. The symptoms depend on how old they are:

●Babies can have pain in their hands and feet, with swelling and redness.

●Older children and adults can have pain in their chest, with trouble breathing, fever, or coughing.

●Older children and adults can have pain in their bones.

Most episodes of pain can't be predicted. But sometimes, the pain can be related to other things, such as:

●Infection – People with sickle cell disease are more likely to get certain infections.

●Dehydration – This is when the body loses too much water.

●Weather or air conditions

●Travel to high-altitude places – These are places where there is less oxygen in the air, such as mountains. Flying in an airplane might also cause symptoms for people with sickle cell disease. Talk to your doctor about what you can do to prevent problems.

People with sickle cell disease can also have other problems, including:

●Severe anemia – "Anemia" means not having enough hemoglobin in the blood. It makes people tired or weak. Most people with sickle cell disease have anemia. But in some cases, it can be severe and need treatment.

●Very severe infections, which can be life-threatening

●Lung problems – Symptoms can include trouble breathing, chest pain, asthma, or sleep apnea. (Sleep apnea is when a person stops breathing for short periods during sleep.) Chest pain, trouble breathing, and fever can be signs of something called "acute chest syndrome." People with acute chest syndrome need to be in the hospital to get pain medicine and antibiotics.

●Strokes – This is when a part of the brain is damaged because of a problem with blood flow. A stroke can happen when a blood vessel gets blocked or bleeds. It can be life-threatening and can cause permanent brain damage.

●Open sores on the skin (usually on the legs)

●A problem with the bone in the shoulder or hip – This happens when the bone doesn't get enough blood, leading to pain. In some cases, this can cause permanent damage. It is called "osteonecrosis" or "avascular necrosis."

●In males, an erection that lasts too long and is very painful – This is called "priapism."

Is there a test for sickle cell disease? — 

Yes. A blood test can show if someone has sickle cell disease.

●All newborn babies in the US are tested for sickle cell disease before they leave the hospital. This test can also show if a baby has sickle cell trait, but parents are not always informed if their baby has sickle cell trait. If a person is not sure if they have sickle cell trait, they can speak with their doctor about how to find out.

●Parents can be tested for the sickle cell gene and other genes before getting pregnant or when they get pregnant. This is to find out their risk of having a baby with sickle cell disease. Your doctor can talk to you about this.

How is sickle cell disease treated? — 

Sickle cell disease involves lifelong treatment. This includes:

●Tests to check for problems the disease can cause – You will have regular appointments and tests for blood counts, kidney function, risk of strokes, and other problems. Find a good doctor who works with you to explain what you need and what your test results mean.

●Hydroxyurea – One of the main treatments for sickle cell disease is a medicine called "hydroxyurea" (sample brand names: Droxia, Hydrea). It helps stop red blood cells from "sickling." This can prevent problems. Children and adults who take hydroxyurea typically live longer, have fewer pain episodes, and are less likely to need to go to the hospital.

The American Society of Hematology has a booklet with more details about hydroxyurea. You can find this, along with more information about sickle cell disease, on their website: www.hematology.org/education/patients/anemia/sickle-cell-disease

●Other medicines – Other medicines might be used if hydroxyurea is not working well enough. Examples include L-glutamine (brand name: Endari) and crizanlizumab (brand name: Adakveo). These can help prevent pain episodes. Your doctor might suggest 1 of these if hydroxyurea is not helping enough with pain or if you cannot take hydroxyurea.

●Medicines to prevent and treat infections – Get all your vaccines, including a flu shot every year. This helps prevent infections. Children might also need some extra vaccines.

Daily antibiotics like penicillin can help prevent infections in young children. Other antibiotics are also used to treat infections when they happen.

It is important for people with sickle cell disease to be treated for infections right away. Call your doctor as soon as possible if you get a fever or think you might have an infection.

●Blood transfusions – This is when a person gets blood that was given by someone else. Children who have a high chance of having a stroke might get blood transfusions to help prevent strokes. People might also get blood transfusions to treat anemia or other problems, or before surgery.

●Folic acid (also called folate) – This is a vitamin that helps people with sickle cell disease make red blood cells.

●Pain medicines – Doctors can use different medicines to treat pain. Your doctor can help you make a plan for treating pain at home. If the pain is severe, people might need treatment in the hospital or regular pain medicines every day.

A procedure called a "bone marrow transplant" or "stem cell transplant" can cure sickle cell disease. This replaces the "stem cells" that make blood with healthy cells. Usually, the bone marrow comes from a sibling without sickle cell disease. (It's OK if they have sickle cell trait.) But this treatment is not done very often. That's because it has many side effects and can only be done if people meet certain conditions.

Gene therapy is also being studied as a way to cure sickle cell disease. It involves using the person's own blood stem cells for a bone marrow transplant. The cells are treated in a lab so they make red blood cells that do not sickle.

When should I call the doctor or nurse? — 

Your doctor or nurse will tell you what to look for and when to call for help. In general, call right away if the person with sickle cell disease has any of the following problems. Do not wait to call, even if it's the middle of the night, because it's important to get treatment right away. Call for help if the person:

●Has trouble breathing

●Has symptoms of a stroke, such as:

•Severe headache

•Seizure

•Not being able to wake up

•Trouble speaking

•Drooping of the face on 1 side

•Weakness in an arm or leg

Some of these stroke symptoms are shown in the picture (figure 2).

●Gets a fever or has other signs of infection (like feeling very tired, loss of appetite, stiff neck, headache, trouble breathing, or cough)

●Has pain that does get better after home treatment

●Has an erection that lasts longer than 2 to 4 hours

What else can people with sickle cell disease do to stay healthy? — 

People with sickle cell disease should:

●See their doctor for regular check-ups, treatments, and tests

●Take all their medicine as instructed.

●Get the vaccines their doctor recommends. Vaccines can prevent certain serious or deadly infections.

●Take good care of themselves, including staying well hydrated, exercising, eating healthy foods, avoiding smoking and air pollution, and getting enough sleep

●Seek support when they need it, and find a doctor who is understanding and caring

What if I have sickle cell disease and want to get pregnant? — 

Talk with your doctor or nurse. A sickle cell specialist or a genetic counselor can do a blood test on your partner and tell you your baby's chance of having sickle cell disease.

Your doctor or nurse will also talk to you about whether you need to stop or change any of your medicines when you start trying to get pregnant. Some medicines are not safe to take during pregnancy. Do not stop taking any medicines without talking to your doctor or nurse first.

If you get pregnant, your doctor will follow you and your baby closely throughout your pregnancy. That's because sickle cell disease can cause problems for both you and your baby.

More on this topic

Patient education: Sickle cell disease pain in adults – Discharge instructions (The Basics)
Patient education: When your child has sickle cell disease (The Basics)
Patient education: Sickle cell trait (The Basics)
Patient education: Vaccines for babies and children age 0 to 6 years (The Basics)
Patient education: Vaccines for children age 7 to 18 years (The Basics)
Patient education: Vaccines for adults (The Basics)
Patient education: Coping with high drug prices (The Basics)
Patient education: Allogeneic bone marrow transplant (The Basics)
Patient education: Therapeutic apheresis (The Basics)
Patient education: Priapism (The Basics)
Patient education: Stroke (The Basics)

Patient education: Vaccines for infants and children age 0 to 6 years (Beyond the Basics)
Patient education: Vaccines for children age 7 to 18 years (Beyond the Basics)
Patient education: Vaccines for adults (Beyond the Basics)
Patient education: Stroke symptoms and diagnosis (Beyond the Basics)
Patient education: Hematopoietic cell transplantation (bone marrow transplantation) (Beyond the Basics)