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What Is Sickle Cell Anemia?

    What Is Sickle Cell Anemia?

    The human body is composed of intricate systems that all have some specific purpose so the body functions as it should. Aside from the organs, the blood also plays a vital role. Blood is mainly responsible for transporting nutrients and oxygen to the different organs. It also collects waste that the body will dispose of. Sickle cell anemia mainly affects the natural functioning of the blood.

    Over time, sickle cell anemia can cause damage to the different organs such as the lungs or the heart. Learn more about this condition’s causes, signs and symptoms, and treatment.

    Sickle Cell Anemia: the Basics

    Sickle cell anemia, also known as sickle cell disease, sickling disorder caused by hemoglobin S, or hemoglobin S or SS disease, is a red blood cell disorder mainly affecting the hemoglobin in blood which is responsible for transporting oxygen and collecting carbon dioxide.

    A healthy person possesses red blood cells with hemoglobin that are smooth and round. This enables red blood cells to easily glide through the blood vessels. However, a person with sickle cell anemia will have red blood cells containing hemoglobin that are rod-shaped. This causes red blood cells to be shaped like crescents or sickles.

    Everything You Need to Know About Anemia

    The sickle-shaped red blood cells are inflexible and sticky, causing them to get stuck or burst when they’re travelling in small blood vessels. Sickle cells also have a shorter lifespan of only 10 to 20 days which means that the body may not be able to replace the red blood cells lost.

    A shortage of red blood cells is called anemia, which is why this disease is called “sickle cell anemia”.

    Anemia vs. Sickle Cell Anemia: What’s the Difference?

    Confusion may arise between anemia and sickle cell anemia. In general, anemia is a term that refers to disorders affecting the red blood cells. Anemia occurs when there is a lack of or a malfunction of the red blood cells.

    Sickle cell anemia is categorized as a type of anemia. However, there are some kinds of anemia that can have different causes.

    Types of Anemia

    Other varieties of anemia include:

    • Iron-deficiency anemia: The body’s inability to properly absorb iron causes this type of anemia, which reduces the amount of red blood cells.
    • Vitamin-deficiency anemia: This is a type of anemia that may result from a poor diet severely lacking in vitamin B12 or folic acid.
    • Aplastic anemia: This happens when the bone marrow fails to produce any cells, including red blood cells.
    • Hemolytic anemia: The destruction of red blood cells in the spleen or blood vessels characterizes this type of anemia.
    • Disease-related anemia: Anemia can develop from conditions affecting the kidney. Chemotherapy can also affect the body’s ability to create more red blood cells.

    Sickle cell anemia is different because this type of anemia is inherited, which means that it can be passed through genes.

    Who Is at Risk?

    Anyone can get sickle cell anemia. This disorder is passed on from generation to generation. However, data shows that people with ancestry located in the following parts of the world are more at risk:

    • Africa
    • The Arabian Peninsula
    • The Mediterranean (in particular, Greece, Turkey, and Italy)
    • South America and Central America
    • Some regions of the Caribbean

    However, it’s important to note that this condition can happen to anyone regardless of their nationality.

    Signs and Symptoms

    Since sickle cell anemia is inherited, symptoms can start showing as early as five months of age. Signs and symptoms include:


    A shortage of red blood cells in the body is called anemia. A person with sickle cell anemia has red blood cells that don’t live as long as healthy ones, which will cause a lack of oxygen in the body. This can lead to fatigue.

    Pain crises

    Acute pain crisis can occur without warning when sickle cells block blood flow and decrease oxygen delivery. A lowered amount of red blood cells, coupled with the immobility of sickle cells, will cause some parts of the body to not receive enough blood. This can cause episodes of pain often referred to as “pain crises”. These episodes can affect any part of the body, such as the chest, joints, legs, arms, or back.

    The duration of these pain crises can range from a few hours to weeks. Sometimes, it can cause severe pain that requires hospitalization. Acute pain crisis can occur without warning when sickle cells block blood flow and decrease oxygen delivery.

    Vision problems

    Sickle cells can block proper blood flow to the small blood vessels in the eyes, damaging or impairing the retina. This can lead to vision problems.

    Swelling in the hands and feet

    Sickle cells, due to their irregular shape, may decrease blood flow to the hands and feet, which can cause swelling.

    Growth irregularities

    A shortage of red blood cells can mean that the body won’t be able to receive enough oxygen and nourishment to grow at the right pace. Children with sickle cell anemia might grow slower compared to other kids.


    Sickle cell disease can cause damage to the spleen, which can result in the body having less protection against certain infections like salmonella or chlamydia.

    Prevention and Treatment

    Unfortunately, since sickle cell anemia is an inherited disease, there’s not much to do to prevent it. If a person has sickle cell anemia, then they will have had it from birth. Currently, treatment for sickle cell disease is a blood and bone marrow transplant. However, this treatment is only effective for younger patients as the procedure is too risky for older people.


    Sickle cell anemia results from an abnormality in the shape of the hemoglobin in the blood, caused by crescent or sickle-shaped red blood cells. This can result in a shortage of red blood cells in the body, or anemia. This disease is inherited, meaning it’s passed on from the genes of parents to their child.

    Learn more about Anemia here.

    Hello Health Group does not provide medical advice, diagnosis or treatment.


    Sickle Cell Disease, https://www.nhlbi.nih.gov/health-topics/sickle-cell-disease, Accessed Aug. 4, 2020

    Sickle Cell Disease, https://medlineplus.gov/sicklecelldisease.html, Accessed Aug. 4, 2020

    Anemia, https://www.hematology.org/education/patients/anemia, Accessed Aug. 4, 2020

    Sickle Cell Crisis (Pain Crisis), https://kidshealth.org/en/teens/sickle-crisis.html, Accessed Aug. 4, 2020

    Sickle Cell Anemia, https://www.mayoclinic.org/diseases-conditions/sickle-cell-anemia/symptoms-causes/syc-20355876, Accessed Aug. 4, 2020


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    Written by Kip Soliva Updated Jun 02, 2021
    Medically reviewed by Jobelle Ann Dela Cruz Bigalbal, MD
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