What Is Sickle Cell Disease?

If you or your child has just been told these words, the most useful question is often a practical one: what does this condition actually mean, day to day? Sickle cell disease is a lifelong, inherited blood condition. You are born with it, it is not caught from anyone else, and its effects come back to one thing — the shape of your red blood cells.

The shape at the heart of it

Healthy red blood cells are soft, round discs. They bend easily, slip through the smallest blood vessels, and carry oxygen from your lungs to the rest of your body. In sickle cell disease, the hemoglobin inside those cells — the protein that holds the oxygen — is a slightly different form, inherited from both parents. Under certain conditions that hemoglobin makes the cells stiffen into a curved, crescent or "sickle" shape instead.

The short video at the top of this page, "Sickle Cell Disease" (a short, 19-second overview), walks through exactly that starting point: it describes the condition as an inherited form of anemia, in which there aren't enough healthy red blood cells to carry adequate oxygen around the body. A second explainer on this site, "What is Sickle Cell Anemia?" (just over a minute), puts it the same way — the abnormal hemoglobin is what distorts the cells. Sickled cells also break down sooner than healthy ones, which is why ongoing tiredness from anemia is such a common part of the picture. If anemia itself is new to you, our overview of what anemia is explains that side of it in plain language.

What a pain episode can feel like

Stiff, sickle-shaped cells do not flow as smoothly as round ones. At times they can bunch together and slow or block blood flow in small vessels, and when tissue downstream gets less oxygen it can hurt — sometimes a lot. These are usually called pain episodes or crises. They can come on in the arms, legs, chest, back or tummy, and they vary a great deal: some settle at home with rest, fluids and warmth, while others need hospital care, and nobody can predict a person's pattern exactly.

Not every ache is a crisis, and people living with the condition often learn their own early signs over time. What matters is knowing in advance — from your own care team — what your plan is when pain starts, rather than working it out in the middle of an episode.

Day-to-day care and the check-ups in between

Between episodes, care is mostly about steady, ordinary follow-up. People with sickle cell disease are usually seen regularly by a blood specialist team, who keep an eye on blood counts, growth in children, and how organs such as the eyes, lungs, kidneys and spleen are doing over the years, because reduced blood flow can affect them gradually. Blood tests, eye checks and other screening are part of that routine monitoring, and keeping vaccinations and general health up to date is commonly discussed at those visits.

Everyday life is not put on hold. School, work, exercise and travel are all part of life with the condition — they just tend to go better with a bit of planning around rest, fluids, temperature extremes and knowing where care is available. Your specialist team can talk through what is sensible for you or your child specifically, because severity varies widely from person to person.

When symptoms need urgent help

Some symptoms should never wait for the next routine appointment. A high fever, chest pain or difficulty breathing, weakness or speech changes on one side, severe pain that is not settling, or a child who looks unusually pale or unwell all need prompt, urgent medical assessment. Sickle cell disease is manageable for many people, but it rewards taking those warning signs seriously and acting early.

Frequently Asked Questions

Is sickle cell disease the same as sickle cell trait?

No. Trait means a person carries one copy of the changed hemoglobin gene and usually stays well, while disease means two copies were inherited and the red cells sickle enough to cause anemia and pain episodes. A blood test can tell which a person has.

Can sickle cell disease be caught from someone else?

No. It is inherited, not infectious — you cannot catch it through touch, sharing food, or being near someone who has it, and it does not spread through blood contact in everyday life.

Does everyone with sickle cell disease have the same symptoms?

No, severity varies a lot between people. Some have frequent pain episodes and complications, others far fewer, which is why follow-up and any treatment plan are tailored by the person's own specialist team.

MedicalVideos.com has published trusted medical videos since 2007. The site was founded by Dr. Mohamed Ibrahim, MD, PhD — physician-scientist.

Educational only — this article is general information about sickle cell disease, not medical advice and not a diagnosis. Fever, chest pain, breathing difficulty, or severe pain that is not settling needs prompt, urgent medical care.