Symptoms of sickle cell anaemia 

Sickle cell anaemia can cause a wide range of symptoms, although not everyone with the condition will experience all of the symptoms.

Sickle cell crisis

Episodes of pain during a sickle cell crisis are one of the most common and upsetting symptoms of the condition.

A sickle cell crisis (also known as a vaso-occlusive episode or VOE) is triggered when the abnormal blood cells block the small blood vessels that supply the body’s tissues.

This damages the cells in the affected tissue, resulting in the tissue becoming swollen, which irritates nearby nerve endings.

During a sickle cell crisis, younger children may develop painful swelling in their hands or feet. This is often the first noticeable symptom.

As a child gets older, pain can occur in any area of the body. However, the most commonly affected areas are the:

  • ribs
  • spine
  • pelvis
  • abdomen
  • sternum (breastbone)
  • long bones in the legs and arms

People with sickle cell anaemia describe the pain as aching, throbbing, sharp and shooting, penetrating or burning.

The pain can be severe and episodes can last from a few minutes to several weeks, with an average duration of around five to seven days.

Children may experience one or two, or as many as 14, episodes a year.

A sickle cell crisis can often occur for no apparent reason, but there are often certain triggers such as:

  • sudden changes in body temperature which can either be from an infection or a change in the outside environment
  • dehydration – when the body loses more fluid than it takes in
  • a sudden shortage of oxygen as a result of exercise, sudden exertion or stress

Potential triggers in older children and adults with sickle cell anaemia include:

  • alcohol
  • cigarettes
  • illegal drugs, such as cannabis and cocaine

It's important to learn what triggers a painful episode so that they can be avoided.


Anaemia, where the amount of haemoglobin in the blood is lower than normal or there are less red blood cells than normal, is a common symptom of sickle cell anaemia. The abnormal cells have a shorter lifespan and aren't replaced quickly enough.

Symptoms include:

  • fatigue – extreme tiredness and a general lack of energy 
  • shortness of breath 
  • palpitations (irregular heartbeat)

Children are often able to compensate for the lack of red blood cells by an increase in heartbeat, although symptoms of fatigue may persist. This can make it difficult to participate in physical activities such as sport.

Aplastic crisis

A more serious type of anaemia called aplastic crisis can occur if your child develops a common childhood infection known as slapped cheek syndrome or parvovirus B19.

The combination of infection and pre-existing anaemia can cause a sharp and sudden drop in the number of red blood cells inside your child’s body.

Symptoms of an aplastic crisis include:

  • very pale skin
  • fatigue
  • headache 
  • fever (high temperature) of 38C (100.4F) or above
  • tachycardia (rapid heartbeat)
  • dizziness
  • fainting

Vulnerability to infection

Children with sickle cell anaemia are more vulnerable to infection, particularly those younger than three years. This is because the abnormal blood cells can disrupt the normal functions of the spleen.

The spleen is an organ found in the abdomen (in the lower left side of the body, behind the stomach). It plays an important role in filtering harmful bacteria and viruses from the blood.

Children with sickle cell anaemia are particularly vulnerable to three types of infection:

As younger children with sickle cell anaemia are at increased risk of developing an infection, daily doses of antibiotics are often recommended as a precaution.

Other vaccinations may also be recommended, such as the Pneumovax, which protects against some types of bacteria that can cause pneumonia; the meningococcal vaccines, which protect against meningitis and septicaemia; and the annual flu vaccinations.

Jaundice and gallstones

Jaundice (yellowing of the skin and whites of the eyes) is a common symptom of sickle cell anaemia. It occurs because the rapid breakdown of abnormal red blood cells leads to a build-up of a waste product in the body called bilirubin.

The build-up of bilirubin often leads to the formation of small crystals called gallstones. Most gallstones don't cause symptoms but they can occasionally block the bile duct, which drains bile from the liver into the bowel. This can trigger jaundice.

More commonly, a gallstone can get stuck in the gallbladder, causing it to become swollen and leading to abdominal pain and nausea.

Avascular necrosis

Avascular necrosis (AVN) is the loss of bone tissue due to a restriction of blood supply.

In children with sickle cell anaemia, AVN usually affects the hip. The first sign can be a limp or pain in the groin. AVN can cause persistent hip pain that can last for several months. In severe cases, it may be necessary for your child to avoid putting weight on the affected leg and they may need to use crutches or a wheelchair.

Less commonly, AVN can affect the shoulder joint or elbow.

Leg ulcer

A leg ulcer is a painful, open sore that develops on the lower leg, usually close to the ankle. Leg ulcers often develop after a skin infection or injury, such as a cut or puncture wound.

Children with sickle cell anaemia have an increased risk of developing leg ulcers. This is because the lack of normal red blood cells means that their leg doesn't receive the nutrients it needs to keep the skin and surrounding tissue healthy.

Delayed growth

Red blood cells provide the oxygen required for physical development. If your child has sickle cell anaemia, it's likely they'll experience delayed growth compared with other children.

Many children with sickle cell anaemia will also experience puberty at a later stage (around 13-14 years of age for girls and 13½-14½ years of age for boys).

The average age of puberty in children who don't have sickle cell anaemia is 11 years of age for girls and 12 years of age for boys.


Priapism is the medical term that describes a persistent and painful erection of the penis. Episodes of priapism can sometimes last for several hours.

Priapism can affect teenage boys and men with sickle cell anaemia because the abnormal blood cells can cause blood to become trapped in the penis.

Priapism doesn't usually develop as a result of sexual stimulation and it can often occur for no apparent reason, usually during a sickle cell crisis.

Teenage boys may be too embarrassed to mention that they're experiencing priapism.

If you have a teenage son with sickle cell anaemia, it's very important that you make them aware of the importance of seeking immediate treatment for priapism.

This is because episodes of priapism that last for more than two hours can permanently damage the penis and may affect your son's ability to obtain an erection in the future.

When to seek urgent medical advice

Because of the risk of the potentially life-threatening complications associated with sickle cell anaemia, it's important that you're aware of any signs or symptoms that your child’s health has suddenly worsened.

Signs and symptoms to look out for are:

  • fever (high temperature) of 38C (100.4F) or above
  • severe pain that develops during a sickle cell crisis that can't be controlled using over-the-counter painkillers
  • breathing difficulties
  • severe abdominal pain or swelling
  • severe headache, stiff neck or dizziness
  • changes in mental state, such as appearing confused or drowsy
  • episodes of priapism (see above) that last longer than two hours
  • seizures (fits)

Contact your GP immediately if your child develops any of the above symptoms. If this isn't possible, take your child to your local accident and emergency (A&E) department.

You can take them by car if they are well enough to travel. However, if this isn't the case, dial 999 to request an ambulance.

It's very important when requesting an ambulance or visiting A&E that you inform all ambulance, medical and nursing staff that your child has sickle cell anaemia. This will ensure that they're aware of the potentially serious nature of your child’s condition.

Sickle cell anaemia

Sickle cell anaemia is an inherited blood disorder in which red blood cells develop abnormally. A specialist nurse explains the condition, and Junior describes living with sickle cell anaemia.

Media last reviewed: 19/07/2014

Next review due: 19/07/2016

Page last reviewed: 21/05/2014

Next review due: 21/05/2016