Kyphosis is curvature of the spine that causes the top of the back to appear more rounded than normal.
While some degree of curvature is normal, a curve of more than 60 degrees is considered a sign of kyphosis.
Sometimes kyphosis does not cause any symptoms other than the back appearing abnormally curved or hunched. However, in some cases the condition causes back pain and stiffness, tenderness of the spine and tiredness.
Back pain can be particularly problematic in adults with kyphosis because the body has to compensate for the spinal abnormality.
If you have severe kyphosis, your symptoms may get worse over time. You may also have difficulty breathing and eating.
What causes kyphosis?
In kyphosis, the middle section of vertebrae (the thoracic vertebrae) is curved out of position. There are a number of reasons why this might happen, including:
poor posture (postural kyphosis) – slouching, leaning back in chairs and carrying heavy bags can stretch supporting muscles and ligaments, which can pull the thoracic vertebrae out of their normal position
abnormally shaped vertebrae (Scheuermann’s kyphosis) – if the vertebrae do not develop in the right way, they can end up being out of position
abnormal development of the spine in the womb (congenital kyphosis) – if something disrupts the spine's normal development, two or more vertebrae sometimes fuse together
Kyphosis can also develop as a result of a spinal injury.
If you have kyphosis, your treatment will depend on how curved your spine is, whether you have any additional symptoms such as back pain, and the underlying causes.
Children with mild kyphosis may not need to be treated because they may grow out of the condition as their body matures. Alternatively, it may be possible to correct the spine using non-surgical treatments, such as bracing.
Kyphosis rarely requires surgical treatment. It's only needed in some severe cases to correct the curvature of the spine.
Older children with kyphosis may become concerned or embarrassed about the effect the condition has on their appearance, or the fact that they have to wear a back brace.
These concerns can affect different children in different ways. Some children can become socially withdrawn and they may be reluctant to take part in activities, such as PE, where their condition may be exposed.
There are no easy answers to these problems. However, it can often help to reassure your child that their condition is only temporary and will improve with time.
Can kyphosis be prevented?
Postural kyphosis can be prevented by being aware of your posture and by taking care of your back. You should encourage your child to:
sit correctly – sit upright, ensuring that the small of the back is supported
avoid carrying heavy schoolbags that can pull on the back muscles and ligaments; the best schoolbags are well-designed backpacks
take regular exercise (see below) to help strengthen the back and keep it flexible; activities such as swimming, running and walkingare ideal for helping to prevent back problems
Explore this guide for information about different types of back pain, ways of preventing it and advice on treatment
Causes of kyphosis
Kyphosis is often caused by poor posture during childhood.
It can also be the result of abnormally shaped vertebrae or developmental problems with the spine.
Your spine extends from your skull to your pelvis. It is made up of 24 individual rectangular-shaped bones called vertebrae, which are stacked on top of one another.
The vertebrae are separated by soft pads, or discs, which act as shock absorbers. The vertebrae are held together by tough bands of tissue called ligaments. Together with the spinal muscles, the ligaments give the back its strength.
In cases of kyphosis, the middle section of vertebrae, known as the thoracic vertebrae, are curved out of position. There are several reasons why the vertebrae can be affected in this way. These are discussed below.
Poor posture in childhood, such as slouching, leaning back in chairs and carrying heavy schoolbags, can cause the ligaments and muscles that support the vertebrae to stretch. This can pull the thoracic vertebrae out of their normal position, resulting in kyphosis.
Kyphosis that is caused by poor posture is known as postural kyphosis.
Abnormal shaped vertebrae
Kyphosis can also be caused when the vertebrae do not develop correctly. They can take on a wedged, triangular shape, rather than the normal rectangular, box-like shape. This leads to the vertebrae being out of position and is known as Scheuermann’s kyphosis.
In people with Scheuermann's kyphosis, the ligaments surrounding the veterbrae can also be thicker than normal which may contribute further to the condition.
It is not known what disrupts the normal formation of the spine. One idea is that the blood supply to the vertebrae becomes disrupted, affecting the growth of the vertebrae. There also appears to be a genetic link, as the condition occasionally runs in families.
Congenital kyphosis is caused when something disrupts the normal development of the spine before birth. In many cases, two or more of the vertebrae fuse together.
It is often unclear why certain children are affected in this way. However, some cases of congenital kyphosis run in families, so it seems that genetics also play a role in this type of kyphosis.
Conditions that cause kyphosis
Conditions that can cause kyphosis include:
osteoporosis – where the bones become weak and fragile and more likely to break (fracture)
spondylosis – a term that describes the general ‘wear and tear’ that occurs in the bones, discs and ligaments of the spine as a person gets older
spina bifida – a condition where the spine has not formed properly
Paget's disease – a condition in which the development of new bone cells is disrupted, resulting in the bones becoming weak
neurofibromatosis – a genetic disorder that affects the nervous system
muscular dystrophy – a genetic condition that causes progressive weakening of the muscles
tuberculosis – a bacterial infection that mainly affects the lungs
cancer that develops inside the spine or spreads to the spine from another part of the body
Kyphosis can also sometimes develop as a result of an injury to the spine.
Kyphosis can usually be diagnosed by examining your spine and taking an X-ray.
During the examination, your GP may ask you to do a number of exercises to assess whether your balance and range of movement are affected.
Your GP may also ask you to lie down so they can see whether the curvature of your spine is caused by bad posture or by a structural problem.
Although it is not always the case, if your spine straightens when you lie down, it is likely that your kyphosis is caused by poor posture (postural kyphosis).
However, if your spine stills curves while you are lying down, it is likely that kyphosis is due to a problem with the structure of your spine, as found in the Scheuermann's or congenital types of kyphosis.
X-ray and scans
An X-ray can usually confirm the diagnosis and determine the cause of the kyphosis.
Further scans are usually only be required if complex treatment, such as surgery, is being planned, or if you have additional symptoms that suggest your nervous system has been affected, such as numbness in your arms or legs.
If you need additional scans you will probably have a:
computerised tomography (CT) scan – where a series of X-rays are taken to build-up a detailed three-dimensional image of your spine
magnetic resonance imaging (MRI) scan – where strong, fluctuating magnetic fields are used to produce a detailed image of the inside of your spine
If you develop kyphosis in adulthood, it is likely that you will need some additional tests to determine the underlying cause.
The tests you will be referred for will depend on any additional symptoms that you have. They may include:
blood tests – which can check for infections such as tuberculosis
a bone density scan – which is a special type of X-ray to assess how strong your bones are; this can be useful for diagnosing conditions that cause weakening of the bones, such asosteoporosis or Paget’s disease
CT and MRI scans
Most cases of kyphosis do not require treatment.
Kyphosis caused by poor posture (postural kyphosis) can usually be corrected by improving your posture.
If a child has kyphosis as a result of abnormally shaped vertebrae (Scheuermann's kyphosis), it will usually improve when they are fully grown.
If you have mild to moderate kyphosis, it may be possible to control your symptoms using painkillers and exercise.
Painkillers and exercise
Over-the-counter painkillers, such as ibuprofen or paracetamol, can help relieve any back pain.
Regular exercise and a course of physiotherapy may also be recommended to help strengthen the muscles in your back.
Teenagers with mild to moderate kyphosis may need to wear a back brace. The brace is worn while the bones are still growing and prevents the curve getting worse.
You may find that wearing a brace is restrictive at first. However, most people get used to them after a while. Modern braces are designed to be as convenient as possible, so you should still be able to take part in a wide range of physical activities.
You will need to wear the brace until you are fully grown, which is usually around 16 years of age for girls and 18 for boys.
Bracing is not usually recommended for adults who have stopped growing because it will not correct the position of the spine.
Surgery can usually correct the appearance of the back and help relieve any painful symptoms. However, as surgery carries quite a high risk of complication, it is only recommended for more severe cases of kyphosis, and where it is felt that the potential benefits of surgery outweigh the risks.
Surgery for kyphosis would usually be recommended if:
the curve of your spine is very pronounced
the curve is causing persistent pain that cannot be controlled with medication
the curve is disrupting your body's other important functions, such as breathing and the nervous system
without surgery it is likely that the structure of your spine would deteriorate further
Surgery is sometimes required for babies born with congenital kyphosis.
A technique called spinal fusion is usually used to treat kyphosis. It involves joining together the vertebrae responsible for the curve of the spine.
During the operation, an incision is made in your back. The curve in your spine is straightened using metal rods and hooks, and your spine is fused into place using bone grafts (where some bone is taken from another place in your body, usually the pelvis). The procedure will take four to eight hours and is carried out under general anaesthetic.
You may need to stay in hospital for up to a week after the operation, and you will usually have to wear a back brace for up to nine months to support your spine while it heals.
You should be able to return to school, college or work after four to six weeks, and be able to play sports about a year after surgery.
Complications of spinal fusion surgery can include:
excessive bleeding at the site of the surgery
accidental damage to the discs of the back
accidental damage to the nerves that run through the spine, which could result in a paralysis with loss of bladder and bowel function
Before deciding whether to have spinal surgery, you should discuss the benefits and risks with the doctor in charge of your care.
Complications of kyphosis
Kyphosis can sometimes cause psychological complications related to body image or physical complications such as nerve problems or loss of bladder or bowel control.
Older children with kyphosis may become self-conscious and embarrassed about the effect of kyphosis on their appearance and body image, or the fact that they have to wear a back brace. Anything that makes them 'stand out from the crowd' can be an issue of concern.
This can affect children in different ways and some children may:
become socially withdrawn
be reluctant to take part in activities that may expose their back or the fact that they have to wear a brace
be reluctant to discuss issues surrounding their treatment, or perhaps argue that they do not need any more treatment
There are no easy answers to these problems, but it can sometimes help to reassure your child that their condition is temporary and will improve with time.
Other complications of kyphosis usually only occur in more severe cases. They include:
persistent pain that cannot be controlled with medication
breathing difficulties that are caused by the spine compressing the lungs and airways
Occasionally, people with kyphosis can have difficulties when the nerves running through the spine become compressed or pinched. This can disrupt nerve signals and cause symptoms such as:
numbness or weakness in your arms and legs
problems with your sense of balance
loss of normal bladder or bowel control (urinary incontinence andbowel incontinence)
Surgery would usually be recommended if you develop these more serious complications.