Sickle cell disease is the most common serious genetic condition in the UK — more common than cystic fibrosis, yet significantly less well understood by the general public, and, I have found in clinical practice, sometimes less well understood by healthcare providers too.
Over 15,000 people in the UK live with sickle cell disease. The majority are of African or Caribbean origin, because the sickle cell gene evolved in regions where malaria was — and remains — endemic. The gene provides some protection against severe malaria in carriers. In people who inherit two copies of the gene, it causes sickle cell disease.
This guide is for patients, carriers, and families.
What happens in sickle cell disease
Normal red blood cells are round and flexible, moving easily through blood vessels. In sickle cell disease, red blood cells contain abnormal haemoglobin (HbS) that causes them to become rigid and crescent (sickle) shaped under certain conditions — low oxygen, dehydration, cold, stress, infection.
Sickled cells cause two main problems:
1. Vaso-occlusion (blocking blood vessels): Sickled cells can clump together and block small blood vessels. This causes a sickle cell crisis — severe pain, typically in the chest, abdomen, back, and limbs. Crises range from mild (manageable at home) to severe (requiring hospitalisation and strong pain relief including opioids).
2. Haemolytic anaemia: Sickled cells break down much faster than normal red blood cells (after about 20 days versus 120 days for normal cells). The bone marrow cannot keep up with production. This causes chronic anaemia — fatigue, pallor, shortness of breath.
Common complications
| Complication | What it is |
|---|---|
| Painful crisis | Sudden severe pain from blocked blood vessels |
| Acute chest syndrome | Lung complication — serious, can be life-threatening |
| Stroke | Blocked blood vessels in the brain — more common in children |
| Splenic sequestration | Sudden trapping of blood in the spleen — emergency in children |
| Avascular necrosis | Death of bone tissue, particularly in hips |
| Eye complications | Damage to retinal blood vessels |
| Leg ulcers | Slow-healing sores from poor circulation |
| Kidney disease | Gradual damage to kidneys |
Case study: Praise and her daughter
Praise came to see me when her daughter Amara, aged 7, was diagnosed with sickle cell disease. Praise and her husband were both carriers (sickle cell trait) — they had not been tested before having children and were unaware of the risk.
"Nobody told us," Praise said. "In Nigeria, nobody mentioned it when we got married."
In the UK, newborn screening detects sickle cell disease at birth (it is part of the heel prick test done at 5 days old). Amara was diagnosed immediately and referred to a paediatric haematologist. She has been on hydroxyurea (a medication that reduces crisis frequency) since age 3.
Amara has had two significant pain crises requiring hospitalisation in 7 years — far fewer than she would have had without prophylactic treatment. She attends mainstream school, plays football, and has a care plan that her school follows.
"I was terrified when she was diagnosed," Praise told me. "The reality has been difficult but manageable. The key was getting into specialist care immediately."
Management — what standard care includes
Sickle cell disease is managed by specialist haematologists, usually in dedicated sickle cell centres. Standard care includes:
Hydroxyurea (hydroxycarbamide): The most important disease-modifying medication. Increases fetal haemoglobin (HbF) production, which reduces sickling. Evidence shows it reduces crisis frequency, acute chest syndrome, and hospitalisation rates by 50% or more. It is significantly underutilised — research shows many patients who would benefit are not on it.
Penicillin prophylaxis: Patients with sickle cell disease are functionally asplenic (their spleen often becomes damaged). This increases risk of serious bacterial infections. Daily penicillin (lifelong for children) is standard.
Folic acid: Daily folic acid supplements support red blood cell production.
Regular blood transfusions: For patients with high stroke risk or frequent severe crises.
Bone marrow transplant: The only potential cure, but requires a matched donor. More accessible for children than adults.
New treatments: Voxelotor and crizanlizumab are newer approved medications that reduce sickling and crisis frequency. Gene therapy trials show significant promise and may become available more widely within the next decade.
If you are a carrier — what you need to know
Sickle cell trait (one copy of the gene) does not cause sickle cell disease. Most carriers are entirely healthy and can live completely normal lives.
However:
- There is a very small increased risk of complications under extreme conditions (extreme exercise at altitude, very severe dehydration)
- If your partner is also a carrier, each pregnancy has a 25% chance of producing a child with sickle cell disease
- Genetic counselling is recommended before having children if you are a carrier
- Free NHS genetic counselling is available — ask your GP
If you do not know your sickle cell status and you are of African, Caribbean, or Mediterranean origin, ask your GP for a sickle cell and thalassaemia test. It is a simple blood test.
Managing a pain crisis at home
Mild crises can often be managed at home with:
- Regular paracetamol and ibuprofen (if tolerated — check with your haematologist)
- Plenty of fluids
- Warmth
- Rest
Go to hospital if:
- Pain is severe and not responding to home analgesia
- You have a fever above 38°C
- You have chest pain or difficulty breathing (could be acute chest syndrome — emergency)
- A child is unusually pale, lethargic, or has a distended abdomen (splenic sequestration)
- You have signs of stroke (sudden weakness, speech difficulty, facial droop)
Sources: NHS Sickle Cell and Thalassaemia Screening Programme; NICE Clinical Guideline NG143 — Sickle Cell Disease (2021); Sickle Cell Society UK — Standards for the Clinical Care of Adults with Sickle Cell Disease (2018); Charache S et al, NEJM 1995 (Hydroxyurea trial).