Pressure ulcers progress through several stages. In the early stages, they may barely break the skin. In later stages, they can involve deep wounds and carry a higher risk of complications, like infection.

Pressure ulcers are also known as bedsores and decubitus ulcers. They range from closed to open wounds and are classified into a series of four stages based on how deep the wound is:

  • Stage 1 ulcers have not yet broken through the skin.
  • Stage 2 ulcers have a break in the top two layers of skin.
  • Stage 3 ulcers affect the top two layers of skin, as well as fatty tissue.
  • Stage 4 ulcers are deep wounds that may impact muscle, tendons, ligaments, and bone.

Bedsores occur most often after a person sits or lies in one position for too long. The immobility cuts off blood circulation to specific parts of your body, damaging surrounding tissues.

Pressure ulcers form mainly on any skin that covers bony areas of the body. Common places for bedsores to develop include:

Two kinds of more severe pressure ulcers do not fit into one of the four stages:

  • suspected deep pressure injury
  • unstageable sores

Pressure ulcers can progress in four stages based on the level of tissue damage. These stages help doctors determine the best course of treatment for a speedy recovery.

If caught very early and treated properly, these sores can heal in a matter of days. If left untreated, severe bedsores may require years to heal.

Stage 1

The first stage is the mildest and affects the upper layer of your skin. In this stage, the wound has not yet opened.


The affected area has no surface breaks or tears but may:

  • appear red in people with lighter skin and blue or purple in people with darker skin
  • remain red or darker for more than 30 minutes after pressure is removed
  • not turn pale if pressed firmly
  • be sore to touch
  • have a warmer temperature from the surrounding normal tissues
  • feel firmer than surrounding tissues
  • cause mild burning or itching


The first step to treating a stage 1 bedsore is to remove pressure from the area. Any added or excess pressure can cause the ulcer to break through the skin surface. If you’re lying down, adjust your position or use pillows and blankets as extra padding.

It’s also important to keep the affected area clean and dry to reduce tissue damage.

Stay well hydrated, and add foods high in calcium, protein, and iron to your diet. These foods help with skin health.


If treated early, developing stage 1 pressure ulcers can heal in about 3 days.

Stage 2

In the second stage, the sore area of your skin has broken through the top layer of skin (epidermis) and some of the layer below (dermis). The break typically creates a shallow, open wound.


A stage 2 bedsore may appear as:

  • a shallow, crater-like wound, or
  • a serum-filled (clear to yellowish fluid) blister that may or may not have burst

It may also cause the following symptoms:

  • some drainage or pus at the ulcer
  • pain
  • swollen, sore, or red tissue around the sore, which indicates tissue death or damage


Similar to treating stage 1 pressure ulcers, you should treat stage 2 sores by removing pressure from the wound. You must seek medical attention for proper treatment.

Your doctor will advise you on specialized wound dressings to keep this area dry and clean. This helps prevent the wound from becoming more severe or infected.

Once you’ve cleaned the ulcer, talk with your doctor about how to bandage it properly. It’s also important to monitor the wound for any signs of infection, including:


Healing from this stage can last anywhere from 3 days to 3 weeks.

Stage 3

Sores that have progressed to the third stage have broken completely through the top two layers of the skin and into the fatty tissue below.


An ulcer in this stage may resemble a hole or crater. You’ll likely notice visible fat tissue but should not be able to see muscle or bone.

In this stage, it’s important to look for signs of infection. These include:


You must seek immediate medical treatment if you have a stage 3 pressure ulcer. These sores need special attention.

Your doctor may prescribe antibiotic therapy and remove any dead tissue to promote healing and to prevent or treat the infection.

If you’re immobilized, your doctor may recommend a special mattress or bed to relieve pressure from the affected areas.


Ulcers in this stage usually need at least 1 to 4 months to heal.

Stage 4

Stage 4 pressure ulcers are the most serious. These sores extend below the subcutaneous fat into your deep tissues, including muscle, tendons, and ligaments. In more severe cases, they can extend as far down as the cartilage or bone.

There’s a high risk of infection at this stage.


You may notice the following symptoms in a stage 4 bedsore:

  • extreme pain
  • drainage
  • dead tissue, which may appear black
  • visible muscles and sometimes bone
  • common signs of infection, like a foul smell and pus
  • a dark, hard substance known as eschar (hardened dead wound tissue)


People with stage 4 pressure ulcers need to be taken to the hospital immediately. Your doctor will likely recommend surgery.


Recovery for this ulcer can take anywhere from 3 months to 2 years to completely heal.

Additional types

In addition to the four main stages of pressure ulcer formation, there are two other categories: unstageable pressure ulcers and suspected deep tissue injury.

Unstageable pressure ulcers are also hard to diagnose because the bottom of the sore is covered by:

  • slough: debris that appears tan, yellow, green, or brown in color
  • eschar: hard plaque that’s tan, brown, or black in color

Your doctor can only determine how deep the wound is after clearing it out. If there’s extensive tissue damage, it will need to be surgically removed.

In certain areas of the body, dry and stable covering shouldn’t be touched. This dry eschar is the body’s natural layer of protection.

Ulcers that form from suspected deep tissue injury can be difficult to diagnose. On the surface, it may resemble a stage 1 or 2 sore. Underneath the discolored surface, this ulcer could be as deep as a stage 3 or stage 4 wound.

This pressure ulcer may also form as a blood blister or be covered with eschar.

Preventative strategies can help reduce the risk of bedsores. These include but are not limited to:

  • changing positions every 2 to 3 hours in bed or every 15 minutes in a wheelchair
  • reducing pressure on areas that may be susceptible to pressure ulcers by using:
    • a special air or gel mattress
    • padding that protects bony areas, like the elbows or ankles
    • a wheel chair cushion
  • skin care as recommended by your practitioner for incontinence
  • regularly checking for bedsores, if you’re immobilized

For patients who meet certain criteria and have health insurance, insurers may cover preventative supplies.

Pressure ulcers are wounds that develop once a pressure injury causes blood circulation to be cut off from particular areas of the body. Damage to affected tissues can be categorized into four stages.

These sores are more common among the elderly, people with limited mobility, and people who are bedridden from illness or other conditions. Though treatable, pressure ulcers can cause a number of complications like infection and the need for amputation. They can take years to heal if not diagnosed and treated early.

If you begin experiencing symptoms with skin changes or pain from immobilization, seek immediate medical attention.