Sickle cell disease can cause a wide range of symptoms.
These can start from a few months of age, although many children have few or no symptoms if treatment is started early on.
Some of the main symptoms are outlined below, although not everyone with the condition will experience all of these.
Episodes of pain – known as sickle cell crises – are one of the most common and distressing symptoms of sickle cell disease. They occur when blood vessels to part of the body become blocked.
The pain can be severe and lasts for up to seven days on average.
A sickle cell crisis often affects a particular part of the body, such as the:
- hands or feet (particularly in young children)
- ribs and breastbone
- legs and arms
How often someone with sickle cell disease gets episodes of pain varies a lot. Some people may have one every few weeks, while others may have less than one a year. The average is one bad episode a year.
It's not always clear what triggers bad pain, but sometimes they can be caused by the weather (such as wind, rain or cold), dehydration, stress or strenuous exercise.
People with sickle cell disease are more vulnerable to infections, particularly when they're young.
This is because the condition can mean the body isn't very good at dealing with bacteria and viruses.
Infections that may occur can range from mild (such as colds), to much more serious and potentially life-threatening (such as meningitis).
Vaccinations and daily doses of antibiotics can help reduce the risk of many infections.
Nearly all people with sickle cell disease have anaemia, where the haemoglobin in the blood is low. Haemoglobin is the substance found in red blood cells that's used to transport oxygen around the body.
This doesn't usually cause many symptoms, but sometimes it can get worse if you become infected with the virus that causes slapped cheek syndrome (parvovirus).
This can lead to a sudden drop in the number of red blood cells and may cause additional symptoms such as headaches, a rapid heartbeat, dizziness and fainting. It's usually treated with a blood transfusion.
In young children, swelling of the spleen can also cause sudden anaemia that requires a blood transfusion.
Sickle cell disease can also sometimes cause a wide range of other problems, including:
- delayed growth during childhood and delayed puberty
- gallstones (small stones in the gallbladder), which can cause tummy (abdominal) pain and yellow skin and eyes (jaundice)
- bone and joint pain
- priapism (a persistent and painful erection of the penis), which can sometimes last several hours
- leg ulcers (painful, open sores on the lower legs)
- strokes or transient ischaemic attacks (where the flow of blood to the brain is blocked or interrupted)
- a serious lung condition called acute chest syndrome, which can cause a fever, cough, chest pain, and breathing difficulties
- swelling of the spleen, which can cause shortness of breath, a rapid heartbeat, abdominal pain, a swollen tummy and worse anaemia
- vision problems, such as floaters, blurred or patchy vision, reduced night vision and occasionally sudden vision loss
- pulmonary hypertension (high blood pressure in the blood vessels that carry blood from the heart to the lungs)
- kidney or urinary problems, including blood in the urine and bedwetting
See treatments for sickle cell disease for information about how many of these problems are treated.