Assessing a wound means looking at it systematically: what’s in the wound bed, how much it’s draining, whether the edges are healing inward, and what the surrounding skin looks like. Whether you’re a nursing student, a caregiver, or someone managing a chronic wound at home, a structured approach helps you track healing progress and catch problems early. The most widely used framework organizes wound assessment into four areas: tissue, infection, moisture, and edges.
Start With the Wound Bed
The tissue inside the wound tells you the most about where healing stands. Healthy healing tissue, called granulation tissue, looks red and moist. It’s well supplied with blood vessels and bleeds easily if disturbed. Seeing a wound bed full of red, bumpy granulation tissue is a good sign.
Not all tissue in a wound bed is healthy. Slough is devitalized tissue made of dead cells and debris. It appears yellow, brown, or grey and sits on the wound surface, slowing healing by acting as a barrier to new tissue growth. Necrotic tissue is a step further: hard, dry, and black. It’s dead tissue that actively prevents healing and typically needs to be removed (a process called debridement) before the wound can progress. When you look at a wound, note what percentage of the bed is covered by each tissue type. A wound that was 80% slough last week and is now 60% granulation is clearly improving.
Check for Signs of Infection
Every wound contains some bacteria, but infection occurs when those bacteria overwhelm the body’s defenses and start damaging tissue. The classic signs are increasing redness, warmth, swelling, and pain around the wound. You might also notice a foul odor or a change in drainage color, particularly to green, yellow, or brown.
It’s worth distinguishing normal inflammation from infection. Some redness and swelling are expected in the early days of any wound as the body sends immune cells to the area. What matters is the trajectory. Redness that’s spreading outward from the wound edges, pain that’s getting worse instead of better, or new thick and discolored drainage all point toward infection rather than routine healing. Fever or red streaks extending away from the wound suggest the infection may be spreading beyond the local area.
Evaluate the Drainage
Wound drainage (exudate) varies in color, consistency, and volume, and each type tells you something different:
- Serous: Clear, thin, watery. This is normal during the early inflammatory stage of healing. Small amounts are expected.
- Sanguineous: Fresh blood. Common immediately after an injury or procedure, or if the wound is disturbed.
- Serosanguineous: Clear fluid with small amounts of blood mixed in. Also typical during normal healing.
- Purulent: Thick, opaque, and can be tan, yellow, green, or brown. This is never normal. New purulent drainage should always be reported to a healthcare provider.
Beyond the type, note the amount. Light drainage that a single dressing absorbs easily is different from heavy drainage that soaks through dressings within hours. Increasing volume can signal infection or a moisture management problem. Decreasing volume over time generally means the wound is progressing.
Measure the Wound
Consistent measurement is the most objective way to track whether a wound is getting smaller. The standard method uses the “clock face” approach: imagine a clock over the wound with 12 o’clock pointing toward the patient’s head. Measure the longest length from 12 o’clock to 6 o’clock, then the widest width from 9 o’clock to 3 o’clock, using a disposable ruler in centimeters. For depth, gently insert a cotton-tipped applicator into the deepest point and mark where it meets the skin surface.
Some wounds develop tunneling or undermining, where tissue destruction extends beneath intact skin at the wound edges. To check for this, gently probe around the wound perimeter with a cotton-tipped applicator. Document the location using clock positions (for example, “2 cm of undermining from 3 o’clock to 5 o’clock”). These hidden pockets can harbor infection and are easy to miss if you only look at the surface.
Examine the Wound Edges
The edges of a wound reveal whether new skin is actively growing inward or whether healing has stalled. In a progressing wound, the edges will be gently sloping toward the wound bed, with a thin band of new pink skin migrating inward. This is called epithelialization, and it’s one of the clearest signs of healing.
When edges are rolled under and thickened (a condition called epibole), new skin cells curl downward instead of growing across the wound surface. This effectively walls off the wound and stops closure. Callous-like tissue forming around the wound edges, known as hyperkeratosis, is another sign that healing has stalled. Both of these findings are scored as more severe on formal wound assessment scales because they indicate the wound needs intervention to restart the healing process.
Inspect the Surrounding Skin
The skin around a wound, called the periwound area, gives important clues about moisture management and overall skin health. Examine at least 4 centimeters out from the wound edge in every direction.
Maceration is one of the most common periwound problems. It happens when wound fluid sits on intact skin too long, breaking down the surface layer of skin cells. White maceration makes the skin look pale, swollen, and wrinkled, like fingers after a long bath. Reddened maceration adds inflammation to the picture. Both indicate that the dressing isn’t handling the drainage volume well enough, or that it needs to be changed more frequently. Wound fluid contains protein-degrading enzymes that are genuinely caustic to intact skin, so maceration isn’t just cosmetic. Left unchecked, it can cause the wound to expand.
Also look for redness (erythema), hardness or firmness beneath the skin (induration), blistering, and any areas where adhesive tape or dressings have stripped away the top layer of skin. Repeated dressing changes are a common cause of periwound damage, particularly in patients with fragile skin.
Assess Blood Flow for Leg Wounds
Wounds on the lower legs and feet heal poorly when blood supply is compromised, so circulation assessment is an important step for any wound below the knee. The ankle-brachial index (ABI) compares blood pressure at the ankle to blood pressure in the arm. A normal reading falls between 0.9 and 1.4.
A value below 0.9 indicates some degree of arterial narrowing. This matters practically because it determines whether compression therapy is safe. With an ABI between 0.5 and 0.8, only light compression should be used. Below 0.5, compression dressings should be avoided entirely, and the patient needs specialist referral. An ABI under 0.5 also significantly increases the risk of amputation in diabetic wounds, with one study showing a 40% increase in likelihood.
Document Everything
A single wound assessment is a snapshot. Its real value comes from comparison over time. Each time you assess a wound, record the date, measurements, tissue types and their approximate percentages, drainage type and amount, edge characteristics, and periwound skin condition. Many clinicians use standardized tools like the Bates-Jensen Wound Assessment Tool, which assigns numerical scores to each category so you can plot a wound’s trajectory on a continuum from “tissue health” to “wound degeneration.”
Even without a formal scoring tool, consistent documentation using the same categories lets you answer the most important question in wound care: is this wound getting better, staying the same, or getting worse? A wound that shows no measurable improvement over two to four weeks with appropriate care is considered stalled and typically needs its treatment plan reassessed.