What's sickle cell disease?
Sickle cell disease is an inherited blood disorder caused by a single change in the HBB gene, which makes an abnormal form of haemoglobin. Red cells become stiff and sickle-shaped, leading to ongoing red-cell breakdown and episodes where blood flow is blocked.
| Also indexed as | OMIM:603903, MONDO:0011382 |
|---|---|
| Features mapped | 12 |
| Treatments mapped | 6 |
| Published sources | 13 |
| Last reviewed | 2026-08-04 |
Signs and symptoms
Recurrent bacterial infections
Infections, including acute respiratory infections, are common in sickle cell disease and can act as triggers for its acute complications.
Priapism
Priapism, a prolonged and painful erection caused by sickled cells blocking blood flow, is a recognized vaso-occlusive complication of sickle cell disease.
Splenic infarction
Blockage of blood flow to the spleen can cause splenic sequestration and infarction, damaging the organ and contributing to the loss of spleen function in sickle cell disease.
Stroke
Sickled cells can block blood vessels in the brain, making stroke one of the serious long-term complications of sickle cell disease.
Autosomal recessive inheritance
Sickle cell disease is inherited recessively: it occurs when a child inherits a sickle HBB gene from each parent, or a sickle gene combined with another abnormal HBB gene.
Hypoxemia
When blood oxygen is low (hypoxic conditions), sickle hemoglobin clumps together inside red blood cells. This sets off a chain of events that reduces blood flow and starves tissues of oxygen.
Abdominal pain
Her belly pain came on suddenly, along with liver damage, bile buildup, the need for blood transfusions, and an enlarged liver seen on imaging.
Increased total leukocyte count
Patients with acute coronary syndrome had higher white blood cell counts along with other signs of inflammation and stress compared to those without the condition.
Hemolytic anemia
Fragile sickled red cells are broken down faster than normal, giving a chronic haemolytic anaemia with fatigue and jaundice.
Vaso-occlusive crisis
A vaso-occlusive crisis is an episode where sickled cells block small blood vessels, causing sudden severe pain. These crises are the most frequent complication of the disease.
Dactylitis
Dactylitis, painful swelling of the hands and feet, is often one of the earliest signs in young children.
Acute chest syndrome
Acute chest syndrome, a serious lung complication with chest pain, fever, and breathing difficulty, is a leading cause of hospitalisation and harm.
How it is diagnosed
Sickle cell anemia
Diagnosed using: Echocardiography.
“The diagnosis depends on echocardiography even if pulmonary artery catheterisation suggests it.”
Sickle cell anemia
Diagnosed using: Magnetic resonance imaging.
“Ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) are the three modalities commonly used on SCD patients to evaluate hepatosplenic involvement, renal pathology, pancreatobiliary disorders, gastrointestinal ischemia, extramedullary hematopoiesis, and genital abnormalities.”
Sickle cell anemia
Diagnosed using: Abdominal ultrasound.
“The US is a first-line imaging tool due to its accessibility and low cost.”
Treatment and management
What the research describes, not a recommendation. Treatment decisions belong with your clinician.
This covers treatments that appear in the published research mapped here. Investigational and experimental therapies are not included, so their absence is a boundary of this map, not a sign they do not exist.
Hydroxyurea
Hydroxyurea is a medicine that raises protective fetal haemoglobin and reduces painful crises, hospitalisations, and mortality in sickle cell disease.
Used to help with: Sickle cell anemia.
“Hydroxyurea reduces morbidity and mortality in children with sickle cell anemia (SCA).”
Gene therapy
Gene therapy is one of several newer treatment options for this blood disorder, but it still has limitations because not everyone can access it, some people don't respond well to it, it can cause harmful side effects, and it doesn't always fully control the disease's complications like anemia and pain crises.
Used to help with: Sickle cell anemia.
“Although hydroxyurea, luspatercept, and curative approaches such as allogeneic transplantation and gene therapy have expanded the therapeutic landscape, major unmet needs persist because of limited access, variable response, toxicity, cost, and incomplete control of anemia, ineffective erythropoiesis, hemolysis, and/or vaso-occlusion.”
Blood transfusion
Blood transfusion is part of the supportive care used in sickle cell disease.
Used to help with: Sickle cell anemia.
“Thalassemia and sickle cell disease (SCD) are among the most common monogenic disorders worldwide and remain associated with substantial morbidity despite advances in supportive care, transfusion practices, and iron chelation.”
Mitapivat
Mitapivat, an oral drug that activates the red-cell enzyme pyruvate kinase, has in studies improved hemoglobin and markers of red-cell breakdown in sickle cell disease, and reduced pain crises among those whose hemoglobin responded.
Used to help with: Sickle cell anemia.
“In SCD, mitapivat consistently improved hemoglobin and hemolysis markers and showed favorable pharmacodynamic effects, with clinically significant reductions in pain crises among hemoglobin responders.”
Allogeneic stem cell transplantation
Allogeneic transplantation, in which a patient receives blood-forming stem cells from a donor, is described as one of the curative approaches for sickle cell disease.
Used to help with: Sickle cell anemia.
“Although hydroxyurea, luspatercept, and curative approaches such as allogeneic transplantation and gene therapy have expanded the therapeutic landscape, major unmet needs persist because of limited access, variable response, toxicity, cost, and incomplete control of anemia, ineffective erythropoiesis, hemolysis, and/or vaso-occlusion.”
Luspatercept
Luspatercept is among the therapies described as expanding the treatment options for sickle cell disease.
Used to help with: Sickle cell anemia.
“Although hydroxyurea, luspatercept, and curative approaches such as allogeneic transplantation and gene therapy have expanded the therapeutic landscape, major unmet needs persist because of limited access, variable response, toxicity, cost, and incomplete control of anemia, ineffective erythropoiesis, hemolysis, and/or vaso-occlusion.”
Triggers to avoid
In this condition, certain drugs, foods, or other exposures can set off an acute episode in people who are affected, even when they are otherwise well. The research mapped here describes the agents below. This is information, not a recommendation: what to avoid and what is safe for any individual is a conversation for their own care team.
Hypoxia
Low oxygen (hypoxia), such as at high altitude, can precipitate a vaso-occlusive crisis and is something to be aware of and avoid where possible.
Reported in the research mapped here as able to provoke: Vaso-occlusive crisis in people with this condition.
“There is still considerable controversy over the site (arteriolar, capillary, or venular) of vaso-occlusion, the type of sickle cell (reversibly sickled or irreversibly sickled) that is primarily involved, and the relative importance of extra-erythrocytic precipitating factors such as stasis, hypoxia, hyperosmolality, acidosis, alteration in temperature, acute-phase rise in plasma proteins and leukocytes, prothrombotic changes in coagulation factors and platelets, and adhesion of blood cells to vascular endothelium (Figure 2).”
Cold exposure
Changes in temperature, particularly cold exposure, can trigger a vaso-occlusive crisis; keeping warm is a common preventive measure.
Reported in the research mapped here as able to provoke: Vaso-occlusive crisis in people with this condition.
“There is still considerable controversy over the site (arteriolar, capillary, or venular) of vaso-occlusion, the type of sickle cell (reversibly sickled or irreversibly sickled) that is primarily involved, and the relative importance of extra-erythrocytic precipitating factors such as stasis, hypoxia, hyperosmolality, acidosis, alteration in temperature, acute-phase rise in plasma proteins and leukocytes, prothrombotic changes in coagulation factors and platelets, and adhesion of blood cells to vascular endothelium (Figure 2).”
Dehydration
Dehydration (reflected as hyperosmolality) can precipitate a crisis, so staying well hydrated is an important everyday measure.
Reported in the research mapped here as able to provoke: Vaso-occlusive crisis in people with this condition.
“There is still considerable controversy over the site (arteriolar, capillary, or venular) of vaso-occlusion, the type of sickle cell (reversibly sickled or irreversibly sickled) that is primarily involved, and the relative importance of extra-erythrocytic precipitating factors such as stasis, hypoxia, hyperosmolality, acidosis, alteration in temperature, acute-phase rise in plasma proteins and leukocytes, prothrombotic changes in coagulation factors and platelets, and adhesion of blood cells to vascular endothelium (Figure 2).”
How to read the evidence labels
Where this comes from
This guide is built from 13 published source(s). Every claim above links back to one of them. Click any source ID to read the original on PubMed.
Take it further
Printed, source-linked documents built from this condition's graph — ready to bring to an appointment or attach to a coverage request. Every claim carries its published source, the same as this guide.