Sickle Cell Anemia: Genetics, Chronic Symptoms, Support

Sickle cell disease is an inherited condition that affects the oxygen-carrying hemoglobin protein in red blood cells. It carries a risk of a sickle cell crisis, pain, infections, and blood clots. The terms "sickle cell disease" and "sickle cell anemia" are used interchangeably.

If you or your child has sickle cell disease, you may have symptoms from time to time, and certain triggers can increase the frequency and severity of symptoms. The disease can be detected with a blood test even when you do not have symptoms.

Treatment for sickle cell anemia includes prevention and management of sickle cell crises and other effects of the condition. This article describes sickle cell disease, the causes, and the treatments.

Illustration of sickle cells in bloodstream — KATERYNA KON/ Science Photo Library / Getty Images

Sickle Cell Anemia, Genetics, and Hemoglobin Mutation

Sickle cell anemia results from a genetic mutation (alteration) in the HBB gene that codes for the hemoglobin protein. Hemoglobin inside red blood cells carries oxygen throughout the body. With this mutation, the gene produces a dysfunctional protein called hemoglobin S (HbS). This gene is inherited from your parents.

Sickle cell trait (HbAS) occurs when you inherit one copy of the mutated gene that codes for HbS from one parent and a copy of the gene that produces normal hemoglobin A (HbA) from the other parent. This is not regarded as having sickle cell disease,

With sickle cell trait, you produce enough normal hemoglobin that you will most likely never have symptoms associated with sickle cell disease, although some can occur.

However, if you have sickle cell trait, you can pass the mutated gene coding for HbS to your children. If a child inherits the gene mutation for HbS from you and a hemoglobin gene mutation from the other parent, they will have sickle cell disease.

Sickle Cell Anemia

Sickle cell disease is more common among certain populations. In the United States, research estimates over 90% of people who have sickle cell disease are Black, around 5% are Hispanic, and about 2% are White.

Types of Sickle Cell Disease

Sickle cell disease can result from mutations within different parts of the HBB gene. This results in dysfunctional hemoglobin proteins and different presentations of sickle cell disease.

These include:

HbSS: If you have inherited the sickle cell gene from both of your parents, you will likely have symptomatic sickle cell disease.
HbS beta thalassemia: You could have this type of sickle cell disease if you inherit a gene for sickle cell disease from one parent and a gene for beta thalassemia (a different kind of hemoglobin disorder) from the other parent. Symptoms can be more severe than other forms of sickle cell disease.
HbSC, HbSD, HbSE, HbSO: You may have one of these sickle cell disease variants if you inherit the sickle mutation of the HBB gene from one of your parents and a different mutation in the HBB gene from the other parent. Symptoms may vary.

Does My Baby Have Sickle Cell Anemia Symptoms?

The symptoms of sickle cell disease and sickle cell anemia are usually episodic, meaning they are not present all the time.

Babies may have nonspecific symptoms (symptoms that can have many causes) such as:

Fussiness
Low appetite
Lower activity than expected for age
Swelling of the hands and feet
Pale or yellowish skin appearance

Usually, diagnosis is made with a screening blood test rather than waiting to see if symptoms develop. If you or your child has a family history of sickle cell disease, blood test screening is crucial to determine whether you or your child has the condition.

What Happens During a Sickle Cell Anemia Crisis?

A sickle cell anemia crisis (also known as a vaso-occlusive crisis) occurs when the blood cells change their shape to resemble a collapsed sickle shape (like the letter "C"), instead of a smooth, round shape with central indentation. This sickle shape results in stickiness of the cells, causing an accumulation of red blood cells that may obstruct blood vessels throughout the body.

Symptoms of a sickle cell crisis can include:

Low energy: Due to low oxygen-carrying capacity of the red blood cells
Pain: Due to obstructed blood flow in the hands or feet
Chest pain, shortness of breath, weakness
Priapism: Pain and obstruction of blood flow in the penis

Any of these symptoms can occur suddenly and may last for days or longer. Sometimes certain triggers may lead to a sickle cell crisis. Triggers can include some medications, certain foods, fevers, stress, and infections.

When to Get Emergency Care for Sickle Cell Disease

Sickle cell disease is a chronic condition. Making sure that you have a healthcare team who is managing your illness is crucial to staying healthy.

Even with regular care, sometimes the effects of the disease can suddenly worsen and be dangerous.

Get prompt medical attention if you experience any of the following:

Shortness of breath
Chest pain
Severe pain in the arms or legs
Swelling of your arms or legs
Weakness or sensory changes on one side of your body
Vision changes
A feeling that you might pass out

Secondary Complications From Sickle Cell Anemia

Over time, sickle cell anemia can cause serious complications. These complications may occur due to the impact of a crisis or due to long-term sickle cell disease.

For some people, sickle cell disease may cause a lower life expectancy, because some of the complications may be severely damaging to health. In fact, people with this disease have approximately a 20-year shorter estimated life expectancy.

Some complications include:

Frequent infections: Due to impaired activity of the spleen, which becomes overloaded with sickled red blood cells
Stroke: Due to obstruction of blood flow within an artery in the brain
Heart disease: May occur due to changes in blood volume, strain on the heart, or blood clots in the coronary arteries (arteries that provide blood to the heart muscle tissue),
Organ failure: As a result of blood clots in organs such as the kidneys, liver, or intestines
Vision loss: Due to oxygen and blood deprivation
Gallstones: Can form as a result of red blood cell breakdown

Treatment Approaches for Sickle Cell Anemia

Several treatment approaches are used for managing sickle cell anemia. These treatments may include medications that help prevent sickling of the red blood cells or clotting of sickled cells.

Other treatment strategies may include preventing crises, managing pain, helping prevent infections, blood transfusions to treat anemia, and treatment intended to cure the disease.

Preventing Symptoms

Medications used to prevent symptoms can be prescribed on a maintenance basis—to be taken on a regular schedule.

These treatments can help reduce the frequency and severity of sickle cell crises:

Oxbryta (voxelotor)
Adakveo (crizanlizumab-tmca)
Droxia, Hydrea, or Siklos (hydroxyurea)

Disease Treatment

There is no cure for sickle cell disease, however, bone marrow transplant has been considered a potential curative therapy. This procedure is a multistep process of depleting the body's precursor red blood cells (immature red blood cells), followed by replacement with healthy red blood cells.

Gene therapies include Casgevy (exagamglogene autotemcel) and Lyfgenia (lovotibeglogene autotemcel). These treatments work by removing cells from the bone marrow, modifying them, and returning them modified cells back to the patient. The modified cells are resistant to sickling, which reduces symptoms of sickle cell disease.

In 2023, The Food and Drug Administration (FDA) approved Casgevy and Lyfgenia for the treatment of sickle cell disease in people 12 years and older who have recurrent vaso-occlusive crises.

These treatments are not a cure for sickle cell anemia but are designed to be a one-time treatment to alleviate symptoms for a lifetime.

Preventing Infections

One of the important aspects of managing sickle cell disease involves the prevention of infections. This condition can make a person susceptible to severe and frequent infections. Penicillin is an antibiotic that is often used in young children who have sickle cell disease to prevent contagious infections that they can be exposed to in early life.

Additionally vaccination against communicable diseases is an important measure to help prevent serious infections.

Pain Management

Treatment of pain that occurs as a complication of sickle cell disease is often adjusted based on the type and severity of pain, your previous response to pain treatments, and whether that treatment is taken at home or in the hospital.

Sometimes over-the-counter treatments such as Tylenol (acetaminophen) or Advil (ibuprofen) can be effective. But chronic use of any pain medication is not safe and may cause side effects.

Healthy Choices With Sickle Cell Anemia

Living with sickle cell disease can be a challenge. Some day-to-day physical and emotional stressors can have a greater impact on a person with sickle cell disease than they do on others in the general population.

Tips for healthy living include:

Maintain a healthy diet.
Do not smoke.
Drink plenty of fluids.
Get enough rest.
Avoid excessive physical exertion.
Avoid injuries whenever possible.
Try to avoid exposure to contagious infections.
Get medical care if you have an injury or develop an infection.

In addition to these lifestyle strategies, you and your hematologist might reconsider your treatment plan periodically to ensure that you are getting the right treatment for the severity of your disease.

The Role of Nutrition in Sickle Cell Disease

Managing Chronic Sickle Cell Anemia Symptoms

Most symptoms of sickle cell disease are intermittent. However, the complications may cause long-term and lasting effects. You may need to make major lifestyle changes to adjust to chronic symptoms that are caused by complications of sickle cell disease.

Lifestyle adjustments may include:

Dietary modifications to prevent complications affecting the digestive system
Physical therapy and rehabilitation after a stroke
Oxygen supplementation for respiratory or heart complications

Sometimes sickle cell disease can result in major disabilities and limitations. You may need to seek accommodations at school or work to help you cope with the chronic or episodic restrictions that are part of your sickle cell disease.

Advocating for Yourself

Often, the symptoms of sickle cell disease do not clearly correspond with diagnostic test results. If you are experiencing symptoms and you feel that you are not getting the attention you need, make sure you ask to see a healthcare provider who is familiar with treating sickle cell disease.

Summary

Sickle cell disease is an inherited blood disorder that can cause distressing symptoms as well as serious health complications. There are several variants of sickle cell disease, and they may range in severity. The condition is present at birth, and it is a lifelong condition.

There are many treatments for sickle cell disease that can help improve quality of life and longevity. There is no widely used definitive cure, but a bone marrow transplant may be an effective treatment for some people.

12 Things You Should Know About Sickle Cell Disease

9 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Centers for Disease Control and Prevention. What is sickle cell disease?
Pokhrel A, Olayemi A, Ogbonda S, Nair K, Wang JC. Racial and ethnic differences in sickle cell disease within the United States: from demographics to outcomes. Eur J Haematol. 2023;110(5):554-563. doi:10.1111/ejh.13936
National Heart, Lung, and Blood Institute. Sickle cell disease symptoms.
Lubeck D, Agodoa I, Bhakta N, et al. Estimated life expectancy and income of patients with sickle cell disease compared with those without sickle cell disease. JAMA Netw Open. 2019;2(11):e1915374. doi:10.1001/jamanetworkopen.2019.15374
Kavanagh PL, Fasipe TA, Wun T. Sickle cell disease: a review. JAMA. 2022;328(1):57-68. doi:10.1001/jama.2022.10233
Food and Drug Administration. FDA Approves First Gene Therapies to Treat Patients with Sickle Cell Disease.
Food and Drug Administration. Casgevy.
Food and Drug Administration. Lyfgenia.
Centers for Disease Control and Prevention. Living well with sickle cell disease.

By Heidi Moawad, MD
Dr. Moawad is a neurologist and expert in brain health. She regularly writes and edits health content for medical books and publications.

See Our Editorial Process

Meet Our Medical Expert Board

Was this page helpful?

Thanks for your feedback!

What is your feedback?

Understanding Sickle Cell Anemia