Pressure Ulcer

Wound and Ulcer Conditions· Also known as: pressure injury, pressure sore, bedsore, decubitus ulcerUpdated Nov 2026

Reviewed by Andrew Schox, BSc(Hons) PGradDipPod MPod, November 2026

At a Glance

A pressure ulcer, also called a pressure injury or bedsore, is damage to the skin and the tissue under it, usually over a bony area such as the heel, hip or tailbone. It is thought to be caused by pressure, shear (skin being dragged or stretched) or friction. About 12.8 per cent of adults in hospital have one, which is over 1 in 10. The first sign is often skin that stays red or darker when pressed. Noticing changes early matters, because ulcers are best managed early.

What is it?

A pressure ulcer is an area of damage to the skin and the tissue under it. It usually forms over a bony part of the body, or under a medical device. Pressure, shear or friction are thought to cause it. Shear is when layers of skin and tissue are pulled in different directions.

It can be mild or serious. At one end is skin that is still unbroken but red, or blistered. At the other end is a deep open ulcer that can reach muscle and bone.

The condition goes by many names, including pressure injury, pressure sore, bedsore and decubitus ulcer. They all describe the same thing.

Who does it affect?

Pressure ulcers are most common in people who move less, have reduced feeling, have poor blood flow or have skin that is already fragile. They happen in hospitals, and also at home and in long-term care.

About 12.8 per cent of adults in hospital have a pressure injury. About 8.4 per cent develop one while they are in hospital. Most of the injuries found are early ones: Stage 1 (about 43.5 per cent) and Stage 2 (about 28.0 per cent). The tailbone area (the sacrum), the heels and the hip are the most affected places.

Your risk is higher if you are seriously ill, older, or have nerve damage such as after a spinal cord injury. Other things linked with higher risk are being unable to move easily, poor nutrition, diabetes, and bladder or bowel incontinence (leaking urine or faeces). These are links, not proof that each one causes ulcers.

Signs and symptoms

The first sign is usually a change in the skin over a bony area. It may look red or darker, or purple or blue on brown or black skin. It may feel warm, hard, spongy, sore, tender, itchy or tingly. If you press the area lightly, the colour stays the same instead of turning white for a moment.

Other early signs include blisters, shiny or bruised-looking patches, and broken or cracked skin. If the pressure carries on, the damage can become an open wound and then a deep ulcer. The skin can change before an ulcer is visible, because tissue damage can begin underneath first.

Some signs can mean something more serious is happening:

Skin that is hot, swollen or red (purple or blue on brown or black skin), pus, a high temperature, or pain that is severe or getting worse can mean the ulcer is infected. An infection can spread to the skin (cellulitis), the blood (septicaemia or sepsis), or to muscle, bone or joint (osteomyelitis). It can also form an abscess (a pocket of pus). These complications can sometimes be life-threatening.
An infection that gets worse quickly, or doesn't respond to antibiotics taken by mouth, can mean the infection is deep or spreading.
A very deep ulcer, one that can't be graded, or several deep ulcers can mean deep tissue damage.
A wound that is getting worse quickly can mean fast-moving tissue damage.
Cellulitis in the leg with a lot of tissue damage may need the dead tissue removed.
Gangrene (tissue death) alongside a foot or Achilles pressure injury is also a serious sign.
A wound caused by cancer can look like a pressure ulcer, or sit alongside one.

What causes it?

When pressure on one part of the body carries on for a long time, it squeezes the tiny blood vessels. The skin and the tissue under it then get less blood. Over time they can be damaged and die.

How much harm is done depends on three things: how strong the pressure is, how long it lasts, and how well your tissues cope with it. Nutrition, blood flow, the moisture on your skin and how much the tissue is squashed or stretched all play a part.

Ulcers most often form over bony areas such as the heels, elbows, hips and tailbone. They can come from lying in bed, sitting in a chair for long periods, or rubbing from a device. Skin that is too dry or too moist is also more easily damaged.

How is it diagnosed?

A pressure ulcer is found by looking at the skin and noting where it is, how deep it goes and what the surrounding skin looks like. Some sources grade it from I to IV. Grade I is discoloured skin. Grade IV is tissue death or damage reaching tendon, joint or bone. Newer systems use Stages 1 to 4 instead.

For a pressure injury on the foot or heel, your podiatrist may also check for other foot problems that can sit alongside it. These include nerve damage, diabetes, callus, deformity, infection, gangrene, an inactive Charcot foot (a past condition that weakens the bones and joints) and poor pulses in the foot, ankle and calf. If these are found, your podiatrist may consider a high-risk foot service.

Risk assessment tools are often used to find people more likely to develop ulcers. Guidelines recommend them, but only weakly. One good-quality trial found that using a tool did not lower the number of new ulcers compared with a nurse's own judgement.

When bone infection is suspected, a bone biopsy (a small sample of bone) is the gold standard test. Exposed bone doesn't always mean the bone is infected. An MRI scan can also suggest infection that isn't there, so it can't settle the question on its own.

Treatment

The best-supported approaches are about lowering risk and caring for the skin. The evidence for treating an ulcer that already exists is thinner.

Looking after it at home

Things that help the skin include:

checking the skin at least once a day for redness or colour change
keeping the skin neither too dry nor too moist
staying as active as possible and moving often
eating a varied, nutritious diet and drinking plenty of fluids
not smoking
avoiding firm massage over bony areas

These come from health-service advice, and the evidence for each is limited.

Treatment from your podiatrist

Your podiatrist looks at the whole foot. For a pressure injury on the heel, foot or Achilles area, they check blood flow, feeling, skin and foot shape. They also look for signs of infection or inflammation.

The best-supported treatment is a pressure-relieving surface. Guidelines strongly recommend an advanced static mattress or overlay for people at increased risk. This lowers the chance of ulcers forming in people who are at risk. It isn't a treatment that heals an ulcer already there. It isn't yet clearly shown how well other preventive measures work compared with usual care.

Other options

If an infection spreads into the soft tissue around the ulcer, a short course of antibiotics of up to 1 week may be used. Longer courses haven't been shown to help, and they can cause side effects, secondary infections and antibiotic resistance.

When bone infection is suspected, antibiotics are usually held until a bone biopsy is done, unless there is sepsis or another urgent reason to start sooner.

Wounds that are very deep, can't be graded, are getting worse quickly or involve widespread tissue damage are often managed by a specialist wound or tissue viability team. Which advanced treatments work best isn't yet clear.

Recovery

How long an ulcer takes to heal isn't yet clear, and it depends on how deep it is and on the person's general health. Treatment is often most effective when the damage is caught early.

Pressure injuries don't follow a set path. A Stage 3 injury may not have started as Stage 1, and a Stage 1 won't always become a Stage 4. Any new skin change matters, whatever number it is given.

Pressure ulcers are linked with more infections, including bone infection. In older people in intensive care, they have been linked with a risk of death two to four times higher. This was not adjusted for other factors, so it doesn't prove the ulcers cause it.

Preventing it

Guidelines strongly recommend an advanced static mattress or overlay for people at increased risk. Daily skin checks help pick up changes early. Moisture balance matters too, as skin that is too dry or too moist is more easily damaged.

Staying active, eating well, drinking plenty of fluids and not smoking also help protect the skin. If someone has urinary or faecal incontinence, the skin around the buttocks needs particular attention. Firm massage over bony areas is best avoided.

Formal risk scales have limited evidence that they reduce the number of new ulcers.

Frequently asked questions

Is a pressure ulcer the same as a bedsore or pressure injury?

Yes. They are all names for the same problem. A newer system calls it a pressure injury and numbers the stages 1 to 4, while older sources say pressure ulcer and use grades I to IV. Many people still say bedsore.

Can a pressure ulcer affect the bone?

A deep ulcer can reach muscle and bone, and infection can spread to the bone (osteomyelitis). Exposed bone doesn't always mean the bone is infected, though. A bone biopsy is the best way to confirm it.

Will a pressure-relieving mattress heal an ulcer?

The strong recommendation is for people at increased risk, to help stop ulcers forming. It isn't proven as a way to heal an ulcer that is already there.

Do pressure ulcers only happen in bed?

No. They can form wherever pressure carries on over a bony area, including when sitting in a chair for long periods. In adults, the heels, hips and tailbone area are the most common places, and ulcers also occur at home and in long-term care.