Sickle Cell Disease: Understanding the Basics

Sickle cell disease is a group of inherited blood disorders. It is present because of genes passed from parents to a child. It is not an infection, and it does not spread through ordinary contact.

The World Health Organization describes the cause as a mutation in the HBB gene, which carries the instructions for haemoglobin. Haemoglobin is the protein in red blood cells that carries oxygen. When a person inherits two copies of the altered gene, one from each parent, they have sickle cell disease. Sickle cell anaemia, in which both copies instruct the body to make haemoglobin S, is the most severe form WHO names.

The U.S. Centers for Disease Control and Prevention describes several types. The type depends on the genes inherited. Alongside haemoglobin S from both parents, a person may inherit haemoglobin S together with another haemoglobin change, such as haemoglobin C or beta-thalassemia. Severity differs. This article does not try to sort one person’s type from another’s. That is a clinical question.

CDC’s overview puts the change in plain sight. Usual red blood cells are round. They move through small blood vessels and carry oxygen. In sickle cell disease, abnormal haemoglobin can make red blood cells hard, sticky, and curved, in the shape that gives the condition its name. Those cells die earlier than usual, so the body is short of red blood cells. They can also jam in small vessels and slow or block blood flow.

WHO connects that blockage to pain and to injury in organs. The fact sheet lists complications that can include sudden episodes of severe pain, anaemia, stroke, serious infections, kidney problems, and risks in pregnancy. CDC adds acute chest syndrome, a dangerous problem in the lungs, among the complications it names. None of this is a checklist for deciding that someone has the condition. Pain and tiredness have many causes. Only a blood test, read by a qualified professional, identifies sickle cell disease.

WHO says sickle cell disease is most common in people of African, Mediterranean, Middle Eastern, and Indian descent. The same fact sheet, citing estimates for 2021, reports about 7.74 million people living with the disease worldwide and about 515,000 babies born with it that year, with nearly 80 percent of cases in sub-Saharan Africa. The concentration is a reason for public awareness. It is not a reason to assume that anyone from those parts of the world has the condition, or that people with other ancestry cannot have it.

CDC notes that in the United States the condition is often found at birth through newborn screening. What a health system offers depends on the country. A global number is context. It is not a description of Samaa Charity Projects’s work, and this organisation has not published impact figures of its own.

A short, accurate account gives people something better than a rumour. It can help a family ask a clearer question, tell disease from trait, and know that testing exists. WHO includes public awareness among the responses to sickle cell disease as a public-health issue. Sharing a sourced explanation is one small part of that. It does not treat anyone.

If you want the distinction between trait and disease, or a closer look at screening, read the other two articles in this series. For a decision about your own health, speak with a qualified healthcare professional. The source pages linked below are the documents this article was checked against.