Pressure ulcers

About pressure ulcers

Pressure ulcers are an injury that breaks down the skin and underlying tissue. They are caused when an area of skin is placed under pressure.

They are sometimes known as “bedsores” or “pressure sores”.

Pressure ulcers can range in severity from patches of discoloured skin to open wounds that expose the underlying bone or muscle.

Read more about the symptoms of pressure ulcers.

How pressure ulcers develop

Pressure ulcers can develop when a large amount of pressure is applied to an area of skin over a short period of time. They can also occur when less pressure is applied over a longer period of time.

The extra pressure disrupts the flow of blood through the skin. Without a blood supply, the affected skin becomes starved of oxygen and nutrients, and begins to break down, leading to an ulcer forming.

Pressure ulcers tend to affect people with health conditions that make it difficult to move, especially those confined to lying in a bed or sitting for prolonged periods of time.

Conditions that affect the flow of blood through the body, such as type 2 diabetes, can also make a person more vulnerable to pressure ulcers.

Learn more about the causes of pressure ulcers.

Who is affected?

It’s estimated that just under half a million people in the UK will develop at least 1 pressure ulcer in any given year. This is usually people with an underlying health condition – for example, around 1 in 20 people who are admitted to hospital with a sudden illness will develop a pressure ulcer.

People over 70 years old are particularly vulnerable to pressure ulcers, as they are more likely to have mobility problems and ageing skin.

Treating and preventing pressure ulcers

Treatment for pressure ulcers includes the use of dressings, creams and gels designed to speed up the healing process and relieve pressure. Surgery is sometimes recommended for the most serious cases.

For some people, pressure ulcers are an inconvenience that require minor nursing care. For others, they can be serious and lead to life-threatening complications, such as blood poisoning or gangrene. 

Read more about the complications of pressure ulcers.

Pressure ulcers can be unpleasant, upsetting and challenging to treat. Therefore, a range of techniques is used to prevent them developing in the first place. These include:

  • regularly changing a person’s position
  • using equipment to protect vulnerable parts of the body – such as specially designed mattresses and cushions

Read about treating pressure ulcers and preventing pressure ulcers for more information.

Unfortunately, even with the highest standards of care, it’s not always possible to prevent pressure ulcers in particularly vulnerable people.

Symptoms of pressure ulcers

The parts of the body most at risk of developing pressure ulcers are those that are not covered by a large amount of body fat and are in direct contact with a supporting surface, such as a bed or a wheelchair.

For example, if you are unable to get out of bed, you are at risk of developing pressure ulcers on your:

  • shoulders or shoulder blades
  • elbows
  • back of your head
  • rims of your ears
  • knees, ankles, heels or toes
  • spine
  • tail bone (the small bone at the bottom of your spine)

If you are a wheelchair user, you are at risk of developing pressure ulcers on:

  • your buttocks
  • the back of your arms and legs
  • the back of your hip bone

Severity of pressure ulcers

Healthcare professionals use several grading systems to describe the severity of pressure ulcers. The most common is the European Pressure Ulcer Advisory Panel (EPUAP) grading system. The higher the grade, the more severe the injury to the skin and underlying tissue. 

Grade 1

A grade 1 pressure ulcer is the most superficial type of ulcer. The affected area of skin appears discoloured – it is red in white people, and purple or blue in people with darker-coloured skin. Grade 1 pressure ulcers do not turn white when pressure is placed on them. The skin remains intact, but it may hurt or itch. It may also feel either warm and spongy, or hard.

Grade 2

In grade 2 pressure ulcers, some of the outer surface of the skin (the epidermis) or the deeper layer of skin (the dermis) is damaged, leading to skin loss. The ulcer looks like an open wound or a blister.

Grade 3

In grade 3 pressure ulcers, skin loss occurs throughout the entire thickness of the skin. The underlying tissue is also damaged, although the underlying muscle and bone are not. The ulcer appears as a deep, cavity-like wound.

Grade 4

A grade 4 pressure ulcer is the most severe type of pressure ulcer. The skin is severely damaged and the surrounding tissue begins to die (tissue necrosis). The underlying muscles or bone may also be damaged.

People with grade 4 pressure ulcers have a high risk of developing a life-threatening infection. 

Causes of pressure ulcers

Pressure ulcers are caused by sustained pressure being placed on a particular part of the body.

This pressure interrupts the blood supply to the affected area of skin. Blood contains oxygen and other nutrients that are needed to help keep tissue healthy. Without a constant blood supply, tissue is damaged and will eventually die.

The lack of blood supply also means that the skin no longer receives infection-fighting white blood cells. Once an ulcer has developed, it can become infected by bacteria.

People with normal mobility do not develop pressure ulcers, as their body automatically makes hundreds of regular movements that prevent pressure building up on any part of their body.

For example, you may think that you are lying still when asleep, but you may shift position up to 20 times a night.

Pressure ulcers can be caused by:

  • pressure from a hard surface – such as a bed or wheelchair
  • pressure that is placed on the skin through involuntary muscle movements – such as muscle spasms
  • moisture – which can break down the outer layer of the skin (epidermis)

The time it takes for a pressure ulcer to form will depend on:

  • the amount of pressure
  • how vulnerable a person’s skin is to damage

Grade 3 or 4 pressure ulcers can develop quickly. For example, in susceptible people, a full-thickness pressure ulcer can sometimes develop in just 1 or 2 hours. However, in some cases, the damage will only become apparent a few days after the injury has occurred. 

Increased risk

There are several factors that increase the risk of developing pressure ulcers. These include:

  • mobility problems – anything that affects your ability to move some or all of your body
  • poor nutrition – for your skin to remain healthy, it requires nutrients that can only be supplied by eating a nutritious diet
  • an underlying health condition that disrupts your blood supply or makes your skin more vulnerable to injury and damage
  • being over 70 years old
  • urinary incontinence and/or bowel incontinence
  • serious mental health conditions

These are discussed in more detail below.

Mobility problems

Possible reasons for having a mobility problem are:

  • having a spinal cord injury that causes some or all of your limbs to be paralysed
  • brain damage caused by an event such as a stroke or severe head injury, which results in paralysis 
  • having a condition that is causing progressive damage to the nerves your body uses to move parts of the body – such as Alzheimer’s diseasemultiple sclerosis (MS) or Parkinson’s disease 
  • having severe pain that makes it difficult to move some or all of your body
  • having a fractured or broken bone
  • recovering from the effects of surgery
  • being in a coma
  • having a condition that makes it difficult to move your joints and bones – such as rheumatoid arthritis 

Poor nutrition

Reasons that your diet may lack nutrition include:

  • anorexia nervosa – a mental health condition where a person has an unhealthy obsession with maintaining a low body weight  
  • dehydration – you do not have enough fluids in your body
  • dysphagia – difficulty swallowing food

Health conditions

Health conditions that can make you more vulnerable to pressure ulcers include:

  • type 1 diabetes and type 2 diabetes – the high levels of blood sugar associated with diabetes can disrupt normal blood flow
  • peripheral arterial disease (PAD) – blood supply in the legs becomes restricted due to a build-up of fatty substances in the arteries
  • heart failure – previous damage to the heart means it is no longer able to pump enough blood around the body
  • kidney failure – the kidney loses most or all of its functions, which can lead to a build-up of dangerous toxins (poisons) in the blood that can cause tissue damage
  • chronic obstructive pulmonary disease (COPD) – a collection of lung diseases; the low levels of oxygen in the blood associated with COPD can make the skin more vulnerable to damage

Ageing skin

There are several reasons why ageing skin is more vulnerable to pressure ulcers. These include:

  • with age, the skin loses some of its elasticity (stretchiness), which makes it more vulnerable to damage
  • reduced blood flow to the skin, due to the effects of ageing
  • the amount of fat under the skin tends to decrease as people get older


Both urinary incontinence (inability to control your bladder) and bowel incontinence (inability to control your bowels) can cause certain areas of the skin to become moist and vulnerable to infection. This can cause pressure ulcers to form.

Mental health conditions

People with severe mental health conditions such as schizophrenia (a condition where people have problems telling the difference between reality and imagination) or severe depression have an increased risk of pressure ulcers for a number of reasons. These include:

  • their diet tends to be poor
  • they often have other physical health conditions, such as diabetes or incontinence
  • they may neglect their personal hygiene, making their skin more vulnerable to injury and infection

Diagnosing pressure ulcers

Pressure ulcers are easily diagnosed by looking at them. However, health professionals prefer to prevent ulcers developing in the first place, so it’s important to assess a person’s risk of developing them.

As part of the risk assessment process, the following will be considered:

  • your general health
  • your ability to move
  • whether you have any problems that may affect your posture
  • whether you have any symptoms that may indicate an infection
  • your mental health
  • whether you have had pressure ulcers in the past
  • whether you have urinary incontinence or bowel incontinence 
  • your diet
  • how well your blood circulation system is working

As part of the risk assessment, you may be referred for blood and urine tests. Blood tests can be a good way of assessing your general state of health and whether your diet is providing enough nutrition.

Urine tests can be used to check how well your kidneys are working and whether you have a urinary tract infection, which can be a cause for concern if you are incontinent or if you have had spinal damage.


If you are thought to be at risk of developing pressure ulcers, but you are not staying in a hospital or care home, you may be advised to regularly check for early signs of the condition.

Look out for areas of discolouration and patches of skin that feel unusually spongy or tough to the touch. Use a mirror to check parts of your body that can be difficult to see, such as your back or buttocks. Contact your GP or your healthcare team if you notice any signs of damage.

Treating pressure ulcers

Treatment for pressure ulcers can vary, depending on the grade of the ulcer. Treatment options may include regularly changing your position, or using special mattresses and dressings to relieve pressure or protect the skin. In some cases, surgery may be needed.

Your care team

Pressure ulcers are a complex health problem arising from many interrelated factors. Therefore, your care may be provided by a team comprising different types of healthcare professionals. This type of team is sometimes known as a multidisciplinary team (MDT).

Your MDT may include:

  • a tissue viability nurse (a nurse who specialises in wound care and prevention)
  • a social worker
  • a physiotherpist
  • an occupational therapist
  • a dietitian
  • medical and surgical experts with experience in pressure ulcer management

Changing position

It’s important to avoid putting pressure on areas that are vulnerable to pressure ulcers or where pressure ulcers have already formed. Moving and regularly changing your position helps to prevent pressure ulcers developing and relieves the pressure on the ulcers that have developed.

After your risk assessment is completed, your care team will draw up a “repositioning timetable”, which states how often you need to be moved. For some people, this may be as often as once every 15 minutes. Others may need to be moved only once every 2 hours.

The risk assessment will also consider the most effective way of avoiding putting any vulnerable areas of skin under pressure whenever possible.

You may also be given training and advice about:

  • correct sitting and lying positions
  • how you can adjust your sitting and lying position
  • how often you need to move or be moved
  • how best to support your feet
  • how to maintain good posture
  • the special equipment you should use and how to use it

Mattresses and cushions

There are a range of special mattresses and cushions that can relieve pressure on vulnerable parts of the body. Your care team will discuss the types of mattresses and cushions most suitable for you.

Those thought to be at risk of developing pressure ulcers, or who have pre-existing grade 1 or 2 pressure ulcers, usually benefit from a specially designed foam mattress, which relieves the pressure on their body.

People with a grade 3 or 4 pressure ulcer will require a more sophisticated mattress or bed system. For example, there are mattresses that can be connected to a constant flow of air, which is automatically regulated to reduce pressure as and when required.


Specially designed dressings and bandages can be used to protect pressure ulcers and speed up the healing process. Examples of these types of dressings include:

  • hydrocolloid dressings – these contain a special gel that encourages the growth of new skin cells in the ulcer, while keeping the surrounding healthy area of skin dry 
  • alginate dressings – these are made from seaweed and contain sodium and calcium, which are known to speed up the healing process

Creams and ointments

Topical preparations, such as creams and ointments, can be used to help speed up the healing process and prevent further tissue damage.


If you have a pressure ulcer, you will not routinely be prescribed antibiotics. These are usually only prescribed to treat an infected pressure ulcer and prevent the infection from spreading.

Antiseptic cream may also be applied directly to pressure ulcers to clear out any bacteria that may be present.


Certain dietary supplements, such as protein, zinc and vitamin C, have been shown to accelerate wound healing.

If your diet lacks these vitamins and minerals, your skin may be more vulnerable to developing pressure ulcers. As a result of this, you may be referred to a dietitian so that a suitable dietary plan can be drawn up for you.


In some cases, it may be necessary to remove dead tissue from the ulcer to help stimulate the healing process. This procedure is known as debridement.

If there is a small amount of dead tissue, it may be possible to remove it using specially designed dressings and paste. Larger amounts of dead tissue may be removed using mechanical means. Some mechanical debridement techniques include:

  • cleansing and pressure irrigation – where dead tissue is removed using high-pressure water jets
  • ultrasound – dead tissue is removed using low-frequency energy waves
  • laser – dead tissue is removed using focused beams of light
  • surgical debridement – dead tissue is removed using surgical instruments, such as scalpels and forceps

local anaesthetic will be used to numb the area of skin and tissue around the ulcer so that debridement does not cause any pain or discomfort.

Maggot therapy

Maggot therapy, also known as larvae therapy, is an alternative method of debridement. Maggots are ideal for debridement because they feed on dead and infected tissue without touching healthy tissue. They also help to fight infection by releasing substances that kill bacteria and stimulate the healing process.

During maggot therapy, the maggots are mixed into a wound dressing and the area is covered with gauze. After a few days, the dressing is taken off and the maggots are removed.

Many people may find the idea of maggot therapy off-putting, but research has found that it is often more effective than more traditional methods of debridement. 


It’s not always possible for a grade 3 or 4 pressure ulcer to heal. In such cases, surgery will be required to seal the wound and prevent any further tissue damage occurring.

Surgical treatment involves cleaning the wound and closing it by bringing together the edges of the wound (direct closure), or by using tissue moved from a nearby part of the body (flap reconstruction).

Pressure ulcer surgery can be challenging, especially because most people who have the procedure are already in a poor state of health. There is a risk of a large number of possible complications occurring after surgery, including:

  • infection
  • tissue death of the implanted flap
  • muscle weakness
  • blisters (small pockets of fluid that develop inside the skin)
  • recurrence of the pressure ulcers
  • blood poisoning
  • infection of the bone (osteomyelitis)
  • internal bleeding
  • abscesses (painful collections of pus that develop inside the body)
  • deep vein thrombosis (a blood clot that develops inside the veins of the leg)

Despite the risks, surgery is often a necessity to prevent life-threatening complications, such as blood poisoning and gangrene (the decay or death of living tissue).

Complications of pressure ulcers

Even with the best possible medical care, complications can arise from grade 3 or grade 4 pressure ulcers and can occasionally be life-threatening.

These complications are discussed below.


Infection can spread from the site of the pressure ulcer to a deeper layer of skin. This type of infection is called cellulitis. It causes symptoms of pain and redness, plus swelling of the skin. It will need to be treated with a course of antibiotics.

Read more information about cellulitis.

Left untreated, there is a risk that the infection can spread to the blood (see below) or the underlying bone or joint. In rare cases, where pressure ulcers involve the lower back, tail bone and spine, the pressure ulcer can spread to the membranes that surround the spine and brain. This is known as meningitis.

Blood poisoning

If a person with a weak immune system has a pressure ulcer that becomes infected, there is a risk that the infection will spread into their blood and other organs. This is known as blood poisoning or septicaemia.

In the most serious cases of blood poisoning, damage to multiple organs can lead to a large drop in blood pressure, known as septic shock, which can be fatal. Symptoms include cold skin and an increased heart beat.

Blood poisoning is a medical emergency. It requires immediate treatment in an intensive care unit (ICU), so that the functions of the body can be supported while the infection is treated with antibiotics or antiviral medication.

Read more information about blood poisoning.

Bone and joint infection

Infection can also spread from a pressure ulcer into underlying joints (septic arthritis) and bones (osteomyelitis).

Both of these infections can damage the cartilage, tissue and bone. They may also affect the joints and limbs.

Antibiotics are required to treat bone and joint infections. In the most serious of cases, infected bones and joints may need to be surgically removed.

Necrotising fasciitis

Necrotising fasciitis, commonly known as “flesh-eating” bacteria, is a serious skin infection that causes rapid tissue death. It can occur when a pressure ulcer becomes infected with a particular type of bacteria, such as Group A streptococci.

Emergency treatment is required. It involves a combination of antibiotics and surgical debridement of the dead tissue.

Gas gangrene

Gas gangrene is a serious but rare form of infection that occurs when a pressure ulcer becomes infected with the clostridium bacteria. The bacteria thrive in environments where there is little or no oxygen. They produce gases and release dangerous toxins. Symptoms of gas gangrene include severe pain and rapid swelling of the skin.

Gas gangrene requires immediate treatment with surgical debridement. In the most serious of cases, it may be necessary to amputate the affected body part to prevent the gangrene from spreading to the rest of the body.

Preventing pressure ulcers

As part of your treatment plan, your care team will discuss with you the best way to prevent pressure ulcers. This will be based on your individual circumstances.

However, you may find that the general advice outlined below is helpful.

Changing position

Making regular and frequent changes to your position is one of the most effective ways of preventing pressure ulcers. If a pressure ulcer has already developed, regularly changing position will help to avoid putting further pressure on it, and give the wound the best chance of healing.

As a general rule, wheelchair users will need to change their position at least once every 15 to 30 minutes. People who are confined to bed will need to change their position at least once every 2 hours.

Once you have developed a pressure ulcer, it’s important that you minimise or avoid putting any further pressure on it to give the wound the best chance of healing.

If you are unable to change position yourself, a carer or relative will need to assist you. For more information and advice about positional changes, read about treating pressure ulcers.


Eating a healthy, balanced diet that contains an adequate amount of protein and a good variety of vitamins and minerals can help prevent skin damage and speed up the healing process. You may be referred to a dietitian so that a dietary plan can be drawn up for you.

If you currently have a reduced appetite due to a pre-existing health condition, the following advice may be useful:

  • Try eating smaller meals throughout the day, rather than 2 or 3 larger meals. Set a timetable for when you should eat, rather than waiting until you feel hungry. This should ensure that you receive the necessary nutrition.
  • Avoid drinking large amounts of fluids just before you are about to eat, as this will make you feel fuller than you actually are.
  • If you find swallowing difficult, try drinking specially made nutritional drinks or puréed foods and soups.
  • If you are a vegetarian, it’s important to eat high-protein alternatives to meat. Cheese, yoghurt, peanut butter, custard, beans and nuts are all good sources of protein.

Read more information about healthy eating for more advice.

Checking your skin

If you have known risk factors for pressure ulcers, it’s important that you check your skin on a daily basis for any signs of pressure ulcers, such as discoloured areas of skin. This is particularly important if you have an underlying condition, such as nerve damage or diabetes, which may dampen or numb feelings of pain in certain parts of your body.

You can use a mirror to check the parts of your body that are difficult to see, such as your bottom and the heels of your feet. If you notice any damage, report it to your care team. If you are at home, contact your GP or community nurse. If you are in hospital or a nursing home, inform one of your nurses or carers.

Quit smoking

If you are a smoker, giving up is one of the most effective ways of preventing pressure ulcers. Smoking reduces the levels of oxygen in your blood. It also weakens your immune system, which increases your risk of developing pressure ulcers.

Read about quitting smoking for further information and advice about giving up smoking.

Last updated:
22 February 2023