How Bed Sores Start and Why They Worsen
Bed sores start when pressure on the skin reduces blood flow for too long. Without enough blood and oxygen, the skin and deeper tissue can become damaged. A bed sore may start as red, purple, blue, or darkened skin and can worsen into an open pressure wound if the pressure continues.
Bed sores are also called pressure sores, pressure wounds, pressure ulcers, or pressure injuries. They can happen in a hospital, nursing home, wheelchair, or at home.
What Causes Bed Sores?
Bed sores are caused by prolonged pressure that reduces blood flow to the skin and deeper tissue.
They usually develop where a bone sits close to the skin, including the:
- Heels
- Tailbone
- Hips
- Ankles
- Elbows
People who can’t easily change positions have a higher risk because pressure stays on the same area longer.
Concerned about your pressure wound?
If you’re concerned about a wound or how it’s healing, professional wound care may help. Submit your information, and we’ll help you find the next step.
Written and medically reviewed by Stephanie Wright, RN, BSN
What Are the Early Signs of a Bed Sore?
The first sign of a bed sore is often a change in the color, temperature, or texture of the skin before an open wound appears.
Watch for skin that:
- Looks red, purple, blue, or darker than usual
- Doesn’t lighten when pressed
- Feels warmer or cooler than nearby skin
- Feels unusually firm or soft
- Looks swollen, shiny, or tight
Skin that stays discolored when pressed is called non-blanchable skin. It can be an early sign of a pressure injury.
Don’t wait for the skin to open before paying attention.
Where Do Bed Sores Usually Develop?
Bed sores usually develop over bony areas where pressure becomes concentrated between the body and a bed, chair, or wheelchair.
Common locations include the:
- Heels
- Tailbone
- Hips
- Ankles
- Elbows
Where a pressure sore develops also depends on how someone spends most of their time sitting or lying down.
Why Do Bed Sores Develop With Immobility?
Bed sores develop more easily with immobility because the body can’t regularly shift pressure away from vulnerable areas.
Most people change position without thinking about it. Those small movements restore blood flow.
Someone who can’t move easily may stay in the same position much longer.
Risk is higher for people who:
- Are on prolonged bed rest
- Use a wheelchair
- Have paralysis or severe weakness
- Are recovering from surgery or illness
- Have reduced sensation
Reduced sensation can make the problem worse because someone may not feel the discomfort that would normally make them move.
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Why Do Bed Sores Get Worse So Quickly?
Bed sores can worsen quickly because pressure may damage deeper tissue before the skin opens.
That means a pressure wound can be more serious underneath the skin than it looks from the outside.
Friction and moisture can make things worse.
Sliding in bed or rubbing against sheets can damage already vulnerable skin. Sweat, urine, stool, wound drainage, and damp clothing can also soften the skin and make it easier to break down.
That’s why a small-looking pressure wound isn’t always a small problem.
Why Don’t Bed Sores Heal Easily?
Bed sores can be difficult to heal because the same pressure that caused the wound may continue after the wound develops.
Healing may also be slowed by:
- Poor circulation
- Poor nutrition
- Dehydration
- Diabetes
- Chronic illness
- Infection
- Reduced mobility
- Reduced sensation
The damage underneath the skin can also be deeper than what you can see.
Bed Sore Isn’t Getting Better?
If a pressure wound is getting deeper, draining, developing an odor, or simply isn’t healing, WoundDock can help you find an appropriate wound-care provider.
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Can a Bed Sore Be Serious Even If It Doesn’t Hurt?
Yes. A bed sore can be serious even when there is little or no pain.
People with diabetes, neuropathy, paralysis, spinal cord injuries, or other causes of reduced sensation may not feel a pressure injury normally.
Pressure can also damage nerves in the area.
Don’t use pain alone to decide whether a pressure sore is serious.
How Do Bed Sores Progress?
Bed sores can progress from skin discoloration to an open wound and eventually deeper tissue damage if pressure continues.
Early Pressure Injury
The skin may still be closed but look red, purple, blue, or darker than usual. It may feel warmer, cooler, firmer, or softer.
Open Pressure Wound
The skin may blister or open. Drainage may develop, and the wound may become deeper.
Advanced Pressure Injury
A severe pressure injury can extend into deeper tissue, including fat, muscle, and sometimes bone.
The deeper the wound becomes, the more difficult it may be to heal.
Can a Bed Sore Become Infected?
Yes. An open bed sore or pressure wound can become infected when bacteria enter damaged tissue.
Watch for:
- Increasing redness
- Warmth or swelling
- Increasing pain
- Pus or unusual drainage
- Foul odor
- Fever or chills
- A wound that’s getting worse
Infection can sometimes spread into deeper tissue or bone.
Pressure wound draining, smelling, or getting worse?
If you’re concerned about a wound or how it’s healing, professional wound care may help. Submit your information, and we’ll help you find the next step.
How Can You Keep a Bed Sore From Getting Worse?
Reducing pressure, protecting the skin, and watching the wound closely can help keep a bed sore from getting worse.
A few things matter most:
Change Position
Changing position takes pressure off vulnerable areas and allows blood to return to the tissue.
There isn’t one repositioning schedule that’s right for everyone. Someone with limited mobility may need an individualized plan.
Check the Skin
Look at pressure areas regularly. Watch for changes in color, temperature, texture, swelling, drainage, or skin breakdown.
Keep the Skin Clean and Dry
Moisture makes vulnerable skin easier to damage. Pay attention to sweat, urine, stool, damp bedding, and wound drainage.
Support Nutrition and Hydration
The body needs protein, calories, fluids, vitamins, and minerals to repair damaged tissue.
Use Pressure-Relieving Surfaces When Appropriate
Special mattresses and cushions can help distribute pressure, but they don’t replace position changes and skin checks.
When Should a Bed Sore Be Seen by a Doctor?
A bed sore should be evaluated when the skin opens, discoloration doesn’t improve, the wound gets deeper, drainage or odor develops, or the wound isn’t healing.
Other reasons to get help include:
- Increasing pain or swelling
- Black or dead-looking tissue
- Increasing drainage
- A foul smell
- Uncertainty about how deep the wound is
You don’t need to wait until a pressure wound looks severe.
A pressure injury can be more significant underneath the skin than it appears from the outside.
When Is a Pressure Wound an Emergency?
A pressure wound may need urgent medical attention when there are signs of serious infection or rapid deterioration.
Seek urgent care for:
- Fever or chills
- Confusion
- Rapidly spreading redness or swelling
- Severe or rapidly worsening pain
- Heavy or foul-smelling drainage
- Rapidly spreading black discoloration
- Significant weakness or illness
- Rapid worsening of the wound
If you believe you’re dealing with a medical emergency, call 911 or seek emergency medical care.
What Kind of Doctor Treats Bed Sores and Pressure Wounds?
Bed sores may be treated by a wound-care specialist, primary-care clinician, surgeon, or another specialist depending on the wound and the patient’s underlying health.
The right provider depends on things like:
- How deep the pressure wound is
- Whether infection is present
- Blood circulation
- Location of the wound
- Mobility
- Other medical conditions
The goal isn’t just to cover the wound.
It’s to understand why it developed, what is preventing it from healing, and how to keep pressure off the area.
Concerned about your pressure wound?
If you’re concerned about a wound or how it’s healing, professional wound care may help. Submit your information, and we’ll help you find the next step.
WoundDock helps patients navigate wound-care options. It does not replace emergency medical care.
References:
- Cleveland Clinic. (2023, February 24). Bedsores (pressure injuries). Cleveland Clinic.
- Shi, C., Bonnett, L. J., Dumville, J. C., & Cullum, N. (2020). Nonblanchable erythema for predicting pressure ulcer development: a systematic review with an individual participant data meta-analysis. The British journal of dermatology, 182(2), 278–286.
- Ahmad, B., Rubio-Sefati, M., & Yacob, M. M. (2023). Incidence and risk factors for pressure injuries in patients who have undergone vascular operations: a scoping review. European journal of medical research, 28(1), 77.
- Gould, L. J., et al. (2024). WHS guidelines for the treatment of pressure ulcers — 2023 update. Wound Repair and Regeneration.
- Boyko, T. V. (2018). Review of the current management of pressure ulcers. Journal of Wound Care.
- Saghaleini, S. H., Dehghan, K., Shadvar, K., Sanaie, S., Mahmoodpoor, A., & Ostadi, Z. (2018). Pressure Ulcer and Nutrition. Indian journal of critical care medicine : peer-reviewed, official publication of Indian Society of Critical Care Medicine, 22(4), 283–289.
- Johns Hopkins Medicine. (n.d.). Bedsores (pressure injuries). Johns Hopkins Medicine.
