Sickle cell disease: symptoms, causes, treatment and screening

NHS inform describes sickle cell disease as the name for a group of blood disorders, of which the most severe is sickle cell anaemia. Red blood cells are usually round, but in sickle cell disease they harden and become sickle-shaped, like a crescent moon. This causes them to die too quickly and block blood vessels, leading to symptoms that are often very painful.

The Sickle Cell Society explains that sickle cell is a disorder of the haemoglobin in the red blood cells, which carries oxygen around the body. People are born with the condition. NHS inform says there are treatments to manage it but no cure yet, and that it is a lifelong condition. The NHS says stem cell or bone marrow transplants and gene therapy are sometimes used to cure sickle cell disease, depending on the type, risks, suitability and donor availability.

The NHS says people with sickle cell disease are usually treated by a doctor and a specialist healthcare team, and the treatments help control symptoms or prevent other problems developing. NHS inform says the team will develop a specialised care plan with you.

For a crisis, NHS inform says it can sometimes be managed at home with painkillers such as paracetamol and ibuprofen, heating pads or warm towels, and staying hydrated, but some people need hospital treatment with stronger pain relief. If self-help does not improve symptoms or the pain is very severe, contact your GP practice, or go to A&E if you cannot.

For people who have regular crises, NHS inform says the healthcare team may recommend medication, usually hydroxycarbamide (hydroxyurea), and that there are also new treatments involving advanced gene editing therapies, which the healthcare team will discuss with you.

The NHS says symptoms can start from 6 months old. It lists pain in the bones, joints, muscles or chest, feeling weak and tired, swelling in the hands and feet, breathing problems, getting infections more often and stomach pain. Other symptoms that sometimes happen include blurred vision, a high temperature or an erection that does not go away or is painful (priapism).

NHS inform lists the main features as crises, infections and anaemia, and other problems such as acute chest syndrome (a lung condition causing chest pain, cough, breathing difficulties and fever), joint and bone pain, delayed puberty or growth, kidney and urinary problems, gallstones, leg ulcers, priapism, high blood pressure, strokes or transient ischaemic attacks, an enlarged spleen and vision problems.

Symptoms affect everyone differently and, for most people, come and go and do not happen all the time, the NHS says. When you are not having a crisis you may feel generally well.

NHS inform says a crisis happens when blood vessels that go to one part of your body become blocked. It usually affects one part of the body at a time, most often the hands or feet, ribs and breastbone, spine, pelvis, tummy, legs and arms. The pain can be severe and can last up to 7 days. Some people have a crisis every few weeks and others much less often.

The NHS names dehydration, sudden temperature change and stress as triggers, and NHS inform adds cold, rainy or windy weather and exercise. NHS inform also suggests avoiding activities that leave you severely out of breath, avoiding alcohol because it causes dehydration, and avoiding extreme temperatures.

• Drink plenty of fluids to avoid dehydration.

• Dress warmly in cold weather, wear layers, and avoid sudden temperature changes and very cold water.

• Keep up to date with vaccinations.

• Try gentle to moderate exercise such as walking or yoga, and avoid high-intensity exercise (NHS).

• Do not smoke or drink alcohol, which can increase the risk of acute chest syndrome (NHS).

The NHS says sickle cell disease is inherited: if both of your parents have the sickle cell gene you will either have the condition or carry the sickle cell trait. NHS inform explains that genes come in pairs, and if you have sickle cell disease you inherit a copy of the sickle cell gene from both of your parents.

The NHS says that if you are a sickle cell trait carrier you do not have the disease and cannot develop it, but you could pass it on if you have children. The Sickle Cell Society says that if you and your partner both have the trait there is a 25% chance any child conceived may have sickle cell disorder and a 50% chance they will have the trait, while if only one of you has the trait, any children will not have the disorder but could have the trait (50% chance).

The NHS says you are more likely to inherit sickle cell disease if your background is African, Caribbean, Mediterranean, Asian (south and southeast) or Middle Eastern.

No. The Sickle Cell Society states that people with sickle cell disorder are born with the condition and it is not contagious; it can only be inherited, from both parents each having passed on the gene for sickle cell.

The Sickle Cell Society says sickle cell trait is not an illness, that people with it do not have symptoms and that most people who have it are healthy. It says anaesthetics can cause problems, so you should always tell your dentist or doctor before treatment, and that there is a small chance of pain at high altitudes (generally above 10,000 feet), including long-haul flying in unpressurised planes and mountain climbing.

It says sickle cell trait is found in 1 in 4 West Africans and 1 in 10 Afro-Caribbeans, and is also found in people who originate from the Mediterranean, Asia and the Middle East. The NHS says you can get a blood test to find out if you are a carrier at any time; talk to a GP.

The NHS says sickle cell disease is usually found during pregnancy or shortly after birth as part of NHS pregnancy and newborn screening. If you are pregnant, you will usually be offered screening by your midwife before 10 weeks, a blood test that checks whether you carry sickle cell genes that can be passed to your baby. You do not have to have the test, but if you decide not to and change your mind later, speak to your midwife or GP.

Most babies are checked as part of the newborn blood spot (heel prick) test, which helps confirm that a baby has sickle cell disease or show whether they are a carrier. The Sickle Cell Society explains that the key reason for newborn screening is that babies with sickle cell disease are vulnerable to serious infections, so identifying them early allows penicillin to be prescribed and referral for specialist care.

It says mortality in childhood sickle cell disease has fallen from 10% in the 1980s to under 1%, almost entirely due to newborn screening, early registration into care and penicillin prophylaxis. It also reports that routine transcranial Doppler screening from the age of 2 years has significantly reduced the burden of stroke, and that hydroxycarbamide should be discussed with parents of all children from the age of 9 months.

NHS inform says children with sickle cell disease should stay up to date with routine vaccinations and that sickle cell disease can cause delayed growth in childhood and delayed puberty.

The NHS says to call 999 if you think you are having a sickle cell crisis with severe pain, breathing difficulties or being sick, if you have sickle cell disease and have a high temperature, or if you have an erection that is painful or does not go away. Do not drive yourself to A&E.

NHS inform lists the following as reasons to phone 999 or go to A&E, and says to tell the healthcare team that you have sickle cell disease.

• A high temperature (fever) of 38C or higher.

• Difficulty breathing.

• Severe pain that is not responding to treatments at home like painkillers.

• Drowsiness, confusion or slurred speech.

• A severe headache, stiff neck, or dizziness.

• Skin or lips that are very pale.

• Fits (seizures).

• Sudden swelling in the tummy.

• A painful erection lasting 2 hours or more.

• Weakness on one or both sides of the body, or sudden vision loss or changes.

NHS inform describes sickle cell disease as a serious, lifelong condition that can be managed well with treatment and self-help to help you live a normal life. The NHS says you will have a healthcare plan and regular check-ups, because the condition increases the risk of complications such as stroke, eye problems and damage to organs such as the lungs, heart and kidneys.

NHS inform says anaemia from sickle cell disease is not the same as iron-deficiency anaemia and that you must not take iron supplements without talking to your healthcare team first, because they can be dangerous. If you are planning to go abroad, talk to your GP practice as far in advance as possible, as you might need extra vaccinations or medication.

The NHS describes screening in pregnancy, covered above. If you have sickle cell disease and are planning a pregnancy, speak to your specialist team, who can give advice specific to you.

On the NHS, sickle cell disease is managed by a specialist healthcare team working with your GP, with emergency care for crises and screening offered in pregnancy and for newborn babies. The NHS signposts the Sickle Cell Society and Contact for support, as well as Sickle Cell & Young Stroke Survivors.

Some people choose a private haematology opinion, for example to talk through medicines, pregnancy planning or transplant suitability. Private care works best when it is coordinated with your NHS team, because your records, monitoring and emergency plan are held there.