The earliest stage of a bed sore is a patch of skin that turns red (or purple/blue on darker skin) and stays discolored even after pressure is removed. The skin is not broken or blistered. It looks like a persistent red mark sitting directly over a bony area, and it won’t turn white when you press on it with your finger. A bed sore can start forming in as little as two hours of unrelieved pressure.
The Blanch Test: How to Confirm What You’re Seeing
The simplest way to tell whether a red spot is an early bed sore or just temporary irritation is the blanch test. Press your finger firmly on the discolored area for a few seconds, then lift it. Healthy skin, or skin that’s just been temporarily compressed, will briefly turn white (blanch) under your finger and then return to its normal color. An early bed sore won’t blanch. The redness stays put, even under direct pressure.
If the redness persists for more than 20 minutes after you’ve completely relieved pressure from the area, that’s a strong signal you’re looking at a Stage 1 pressure injury rather than a normal skin response.
What It Looks Like on Darker Skin
On darker skin tones, the classic red patch may not be visible at all. Instead, the area may appear purple, bluish, or unusually shiny compared to the surrounding skin. The blanch test is less reliable here because the color change is harder to see, so you’ll need to rely more on touch and sensation. The spot may feel noticeably warmer or cooler than the skin around it, firmer or harder than normal, or slightly swollen. Any persistent discoloration over a bony area that differs from the surrounding skin deserves attention, even if it doesn’t look “red” in the traditional sense.
What It Feels Like Before You Can See It
In many cases, a bed sore announces itself through sensation before it’s clearly visible. The person may report localized pain, tenderness, itching, or a burning feeling over a bony spot. The skin in that area may also feel different to the touch: harder, softer, boggier, or a different temperature than the skin nearby. These changes in firmness and temperature can actually precede any visible color change, making them the earliest detectable warning signs.
Where to Check First
Bed sores form where bone presses skin against a surface, in areas with little muscle or fat padding. The specific hotspots depend on position.
For someone who is mostly in bed, check the tailbone and lower back, shoulder blades, heels, back of the head, ankles, hips, and the skin behind the knees. For someone in a wheelchair, the most common locations are the tailbone and buttocks, shoulder blades and spine, and the backs of the arms and legs where they rest against the chair. Heels and elbows are vulnerable in both situations.
A good rule: if the area is directly over a bone and the person has been in one position for an extended time, it’s a prime location for pressure damage.
Bed Sore vs. Moisture Rash
Because bed sores often form in areas that also get sweaty or exposed to incontinence, it’s easy to confuse an early pressure injury with a moisture-related rash. A few key differences help sort them out.
- Location: A bed sore sits over a bony prominence in a single, defined spot. A moisture rash tends to appear in skin folds or spread diffusely across a broader area.
- Shape: Early bed sores are typically circular or have a regular, distinct outline. Moisture damage looks more scattered, with multiple superficial irritated spots or a diffuse redness.
- Cause: If the skin was wet or in contact with urine or stool, moisture is the likely culprit. If the area has been under sustained pressure against a surface, pressure is more likely. Both can be present at the same time.
- Pattern: A rash confined to the anal cleft in a linear shape, or redness fanning out around the peri-anal area, points toward moisture damage rather than a pressure injury.
What to Do When You Spot One Early
A Stage 1 bed sore is the only stage that can fully reverse. The skin isn’t broken yet, and removing pressure gives the tissue a chance to recover. The most important immediate step is getting all pressure off the affected area. Don’t position the person on the discolored spot at all until the skin returns to normal.
Repositioning should happen every two to three hours for anyone at risk, and more frequently if early skin damage is already present. Each time you reposition, check the skin over bony areas for new discoloration or temperature changes. The goal is to catch problems before they progress, because once the skin breaks open, healing becomes significantly harder and slower.
Keep the skin clean and dry, but avoid scrubbing or massaging the discolored area, which can cause further damage to already compromised tissue. A pressure-redistributing mattress or cushion helps spread body weight more evenly and reduces the force on vulnerable spots.
When an Early Spot Signals Deeper Damage
Not every intact patch of discolored skin is a simple Stage 1 injury. If the area appears purple or maroon rather than red, it may indicate a deep tissue pressure injury, where damage has already occurred in the muscle and fat beneath the skin even though the surface looks unbroken. This type of injury can feel painful, firm, or mushy, and the skin temperature in the area is often noticeably different from the surrounding tissue. A deep tissue injury can deteriorate rapidly over the following days, sometimes revealing a much more serious wound as the damaged layers break down. Purple or maroon discoloration, especially over a bony area, warrants prompt professional evaluation rather than a wait-and-see approach.