Sickle cell disease

Sickle cell disease is the name for a group of blood disorders, and the most severe of them is sickle cell anaemia. These disorders are inherited, which means they are passed on through your genes.

You can have a blood test at any time to find out if you carry the gene for sickle cell disease, or if you have the disease itself.

The disease affects how your body makes red blood cells. Normal red blood cells are round. In sickle cell disease they harden and become sickle-shaped, like a crescent moon. This makes them die too quickly and block blood vessels, and that leads to symptoms that are often painful.

Some ethnic backgrounds carry a higher chance of having the disease or carrying the gene. You are more likely to have sickle cell disease if you are from one of these backgrounds:

• African
• Asian
• Caribbean
• Eastern Mediterranean
• Middle Eastern

There are treatments to manage the condition, but there is no cure yet. It's a lifelong condition.

Sickle cell disease shows itself in three main ways: sickle cell crises, infections and anaemia. A crisis is a very painful episode that can affect different parts of the body.

Sickle cell disease can cause a number of serious problems that appear suddenly. If you have any of these symptoms, get medical advice immediately:

• high temperature (a fever) going to 38C (100.4F) or higher
• difficulty breathing
• drowsiness, confusion, or slurred speech
• a severe headache, stiff neck, or dizziness
• skin or lips that are very pale
• fits (seizures)
• serious pain that isn't responding to treatments at home
• sudden swelling in the tummy
• priapism, a painful erection lasting two hours or more
• weakness on one or both sides of your body
• sudden vision loss, or changes in your vision

If you develop any of these symptoms, phone your doctor or care team immediately. If you can't reach them, go to your nearest hospital emergency department (the Accident and Emergency department). Dial 999 for an ambulance if you aren't able to travel yourself.

Make sure the medical team looking after you know that you have sickle cell disease.

Sickle cell crises are episodes of pain that happen when the blood vessels going to one part of your body become blocked. The pain can be severe.

Crises are one of the most common symptoms of sickle cell disease. On average, a person has one about once a year, and it lasts up to seven days. Some people have a crisis every few weeks, while others have them less than once a year.

A sickle cell crisis usually affects one part of the body at a time. The parts most often affected are:

• hands or feet (this is especially common in young children)
• ribs and breastbone
• spine
• pelvis
• tummy
• legs and arms

The causes of a crisis differ from person to person. Cold, rainy or windy weather can bring one on, and so can stress, dehydration, or exercise that leaves you severely out of breath.

Sickle cell disease makes people, and children especially, more likely to pick up infections, because their bodies don't deal with bacteria and viruses as well as they should. That means they catch things like the common cold more easily. They are also at greater risk of severe, potentially life-threatening illnesses such as meningitis.

Many people with sickle cell disease take antibiotics every day to prevent infection, and they also keep their vaccinations up to date.

Almost everyone with sickle cell disease has anaemia. Haemoglobin is the substance in red blood cells that carries oxygen around the body, and people with anaemia have low levels of it in their blood.

Most of the time the anaemia doesn't cause symptoms. But if you get infected with parvovirus, the virus that causes slapped cheek syndrome, the anaemia can get worse. When that happens, it causes:

• headaches
• a fast heartbeat
• fainting
• dizziness

If these symptoms occur, the anaemia is usually treated with a blood transfusion.

Young children can also develop sudden anaemia if their spleen swells. This is treated with a blood transfusion too.

Sickle cell disease can cause many other problems too. These include:

• a serious lung condition called acute chest syndrome, which can cause chest pain, a cough, breathing difficulties and fever
• pain in bones and joints
• delayed puberty
• delayed growth in childhood
• kidney or urinary problems, including bedwetting and blood in the urine
• gallstones, which are stones in the gallbladder that can cause jaundice (yellow eyes and skin) and abdominal (tummy) pain
• ulcers on the lower legs (open sores that can be very painful)
• priapism, a painful, persistent erection that can last for several hours
• high blood pressure (pulmonary hypertension)
• transient ischaemic attacks (TIAs) or strokes, which happen when blood flow to the brain is interrupted or blocked
• enlarged spleen, which can cause a fast heartbeat, worsening of anaemia, a swollen tummy, shortness of breath and abdominal pain
• vision problems like floaters, worsened night vision, blurred vision, patchy vision and, occasionally, sudden vision loss

These symptoms can be treated. See Treating sickle cell disease for more information.

You can have a blood test at any time to find out if you have sickle cell disease, or if you're a carrier who could have a child with the condition.

Sickle cell disease is usually diagnosed during pregnancy, when screening can show whether a baby is at risk of having it. Even if your family background doesn't make it likely your child will have sickle cell disease, you can still ask for a test.

If possible, screening should be done before the tenth week of pregnancy. That leaves time to think about further tests that can find out if your baby will be born with the condition.

Newborn babies are also screened as part of the newborn blood spot test, the heel prick test. There are a few reasons for this:

• if a baby's parents weren't screened during pregnancy, this test identifies if the child has sickle cell disease
• if screening during pregnancy showed the baby had a high risk of having sickle cell disease, but no more testing was done, the heel prick test will show if the child has the condition or not
• this test shows if the baby is a carrier of sickle cell, and could one day have children of their own who have the condition (find out more about sickle cell carriers)
• the heel prick test identifies other inherited conditions, like cystic fibrosis

If the heel prick test suggests the baby could have sickle cell disease, another blood test is used to confirm the diagnosis.

Learn about being tested to see if you carry the sickle cell gene

People of any age with sickle cell disease are looked after by a team of medical professionals at a specialist sickle cell centre. The team will work out a care plan with you, so that you understand the condition properly and can find the best way to manage it.

Sickle cell crises can usually be managed at home. These steps are recommended for adults or children having a sickle cell crisis:

• Over the counter painkillers like paracetamol and ibuprofen can help, but aspirin should not be given to anyone under 16. If needed, your doctor may prescribe stronger painkillers.
• Heating pads or warm towels can be placed on the area and massaged to ease the pain. Pharmacies usually sell heating pads you can use for this.
• Drink plenty of fluids, because staying hydrated will help.
• Relaxing distractions like reading, videos and computer games are a good way to take your mind, or your child's mind, off the pain.

If none of these steps help, or the pain is very severe, phone your doctor. If you can't reach a doctor, you or your child should go to the local hospital emergency department. You or your child may need to spend a few days in hospital being treated with stronger pain relief.

The best way to prevent a sickle cell crisis is to know the possible triggers and avoid them.

• Prevent dehydration by drinking plenty of fluids, especially water.
• Avoid alcohol, because alcohol causes dehydration.
• Stay warm with enough layers of clothing so you don't get cold, and avoid extreme temperatures.
• Avoid sudden changes in temperature. For example, don't swim in cold water.
• The lack of oxygen at high altitudes can trigger a sickle cell crisis, so be careful if you're at high altitude for any reason. Plane travel shouldn't be a problem, though, because planes are pressurised and keep the oxygen level consistent.
• Make sure you stay active, but avoid activities that leave you severely out of breath.
• Don't smoke, because smoking can trigger acute chest syndrome.
• Stay as relaxed as you can. Stress can trigger sickle cell crises, so consider learning relaxation techniques like breathing exercises.

Your care team may recommend a medicine called hydroxycarbamide (hydroxyurea) if you keep having sickle cell crises. It's a capsule that you take once a day. It works by reducing how many other types of blood cell, like white blood cells and platelets (clotting cells), there are in the body.

This means you'll need regular blood tests to make sure you're healthy.

Children with sickle cell disease should keep up to date with all their routine vaccinations. Some may also need extra ones, such as the hepatitis B vaccine and the yearly flu vaccine.

If you have sickle cell disease, you will most likely need to take a dose of antibiotics every day, usually penicillin. This does not carry serious health risks.

In your day-to-day life, be careful about activities that can make you more open to infection. Always follow good food hygiene, for example.

If you're planning to go abroad, talk to your doctor as early as you can. You might need extra vaccinations or medicine, such as anti-malarials if you're going somewhere malaria is a risk. It may also be a good idea to take extra care with food and water.

Most of the time, the anaemia in sickle cell disease causes no symptoms, and you won't need any treatment for it. Children with sickle cell anaemia who also follow a restricted diet (such as a vegan or vegetarian diet) may need folic acid supplements, though. Folic acid helps your body make more red blood cells, so it can help improve the anaemia.

This type of anaemia isn't the same as the anaemia caused by iron deficiency. So don't take iron supplements without talking to your care team first, because iron supplements can be dangerous when the anaemia is caused by sickle cell disease.

Blood transfusions or hydroxycarbamide may be needed if the anaemia is serious or doesn't go away.

Sickle cell disease can cause several other problems, and the treatment depends on the type of symptom and how severe it is:

• People with acute chest syndrome need emergency treatment. This means oxygen, blood transfusions, antibiotics, and fluids given through a vein, and possibly hydroxycarbamide to stop it happening again.
• Painkillers can treat joint and bone pain.
• Children with delayed puberty can be given a short course of hormones to trigger it.
• Gallstones are treated with surgery to remove the gallbladder.
• For persistent priapism, medicine can be used to stimulate blood flow, or a needle can be used to drain blood from the penis.
• People who have had a stroke, or who are at greater risk of having one, are given regular blood transfusions or hydroxycarbamide.

Chelation therapy is used as well, on top of the treatments above. It involves taking medicine to lower the level of iron in your blood and bring it down to safe levels. It is given to people who need a lot of blood transfusions.

Sickle cell disease is a lifelong illness, but with treatment and some self-help it can be managed well. You can try to prevent symptoms and crises as much as possible, and there are also a few things you can do that will make life with the condition easier and help you stay in the best health you can.

If you have sickle cell disease and you're due to have surgery, or you're rushed in for emergency surgery, you need to take some precautions. This matters a great deal.

Tell your care team about any surgery you have planned that involves a general anaesthetic. On the day itself, tell your surgeon again that you have sickle cell disease.

General anaesthetic can cause a number of problems, and one of them is a higher risk of a sickle cell crisis. So you should be watched closely during the operation, given plenty of fluids, and kept warm.

You may also need a blood transfusion before the surgery, to lower the chances of complications.

You can have a healthy pregnancy with sickle cell disease, but it's a good idea to talk to your doctor before you plan one. There are several reasons for this:

• there's a bigger chance of complications while you're pregnant, such as miscarriage, pre-eclampsia, anaemia and sickle cell pain
• you may have to stop taking some of the medicines for sickle cell disease, like hydroxycarbamide, before you get pregnant, because these can harm a foetus
• it may be a good idea to find out if your partner is a sickle cell carrier and talk with a counsellor about what this could mean
• extra monitoring during pregnancy, as well as extra treatment, might be necessary

If you aren't planning a pregnancy, use a reliable form of contraception.

Most children with sickle cell disease lead normal, happy lives. But the condition can be very different from one person to the next, and it is still a serious one.

Sickle cell disease can have a big effect on someone's life. It can lead to serious infections, strokes and transient ischaemic attacks (TIAs), and lung problems, which can be fatal.

Life expectancy for people with sickle cell disease is shorter than normal. How much shorter depends on the type of sickle cell disease, what problems the person has, and how the condition is treated.

Milder types of sickle cell disease may not affect life expectancy. People with sickle cell anaemia have a typical life expectancy of between 40 and 60 years of age. As newer treatments are developed, it's hoped that the outlook will get better.

Sickle cell disease comes from a problem in a gene, and you inherit that gene from your parents. You can't catch it from another person. Nor is it caused by anything your parents did, either before or during the pregnancy.

You get one set of genes from your mother and one from your father, so genes always come in pairs. A child born with sickle cell disease has inherited a copy of the sickle cell gene from both parents, which means both genes in the pair are faulty.

This happens when both parents are "carriers". They carry the faulty gene for sickle cell, which is also called having the sickle cell trait. Carriers don't have sickle cell disease themselves, but if their partner is a carrier too, they may have a child with the condition.

When both of a child's parents are sickle cell carriers:

• there's a 25% (one in four) chance that each of their children won't inherit any faulty genes. That child won't have sickle cell disease, and won't be able to pass it on to their own children
• there's a 50% (one in two) chance that each child will inherit a copy of the faulty gene from just one parent, and be a sickle cell carrier
• there's a 25% (one in four) chance that each child will inherit copies of the sickle cell gene from both parents, and have sickle cell disease when they're born

The Sickle Cell Society has more information about how sickle cell disease is inherited.

Sickle cell disease carriers are people who have the faulty gene that causes sickle cell disease but don't have the disease themselves. You may also hear this called having the sickle cell trait.

If you have the sickle cell trait, you won't develop sickle cell disease. There is a risk, though, that you'll have a child with the condition, or a child who is also a carrier.

Anyone can carry the sickle cell gene, but some people are much more likely to be carriers because of their ethnic background.

You are more likely to be a carrier if your family comes from one of these areas:

• Africa
• Asia
• The Caribbean
• The Eastern Mediterranean
• The Middle East

Most sickle cell carriers in the UK have an African or Caribbean family background. It's estimated that around one in ten people with this background may be a sickle cell carrier.

You can ask your doctor for a blood test at any time to find out if you're a sickle cell carrier. It's a particularly good idea if your family background makes it more likely that you have the gene. Both men and women can have the test.

Every pregnant woman is offered screening to check whether her baby is at risk of being born with sickle cell disease. You can ask for a test even if your family background doesn't suggest your child will have sickle cell disease. It's also a good idea to have your partner screened for the gene.

If possible, screening should be done before the tenth week of pregnancy. That leaves time to think about further tests that can find out if your baby will be born with sickle cell disease.

If you carry sickle cell, you are not at risk of developing sickle cell disease.

The only time a carrier may face health problems is in rare cases where the body might not get enough oxygen. These are some of the situations:

• having surgery under general anaesthetic. Tell your medical team before the operation that you carry sickle cell, so they can make sure you get enough oxygen
• extreme sports such as deep sea diving and climbing at high altitudes. If you do sports like these, make sure you're never short of oxygen
• regular, intensive physical activity. Drink plenty of fluids during training and avoid extreme exhaustion

There's also a very small risk of kidney problems linked to carrying sickle cell.

Apart from these uncommon situations, you can lead a completely normal and healthy life as a sickle cell carrier.