Recognizing Wound Infection at Home: Signs Every Diabetic Foot Patient Should Know
patienteducation
A deep dive into the specific signs of diabetic foot ulcer infection — from subtle warmth and odor to systemic red flags — and exactly when to call your clinician.
Infection is the complication that turns a manageable diabetic foot ulcer into a limb-threatening emergency. Because neuropathy blunts pain, patients often miss the early signals. This guide covers what to look for and what each sign means.
Local signs at the wound
- Increasing redness that spreads beyond the wound edge, especially a red streak moving up the foot or leg.
- Warmth — the skin around the wound feels noticeably hotter than the same spot on the other foot.
- Swelling that was not there yesterday, or a dressing that suddenly feels tight.
- Change in drainage — thicker, cloudy, green, brown, or bloody where it was clear before.
- Odor — a new foul or sweet smell, even after cleansing.
- Wound bed color — new black or gray tissue, or granulation tissue that was pink and is now dull.
Systemic signs
- Fever above 100.4°F (38°C) or chills
- New fatigue or confusion, especially in older patients
- Blood sugar that suddenly runs high without dietary change — often the earliest systemic clue in diabetes
- Nausea or loss of appetite
What is NOT infection
The inflammation phase of healing includes mild redness and swelling for the first few days. It is localized, stable, and improving — not spreading. A changing wound bed color as tissue rebuilds is also normal.
When to act
- Same day call: new odor, spreading redness, increased drainage, fever, or high blood sugar.
- Emergency room: red streaks up the leg, black tissue, severe pain, or systemic symptoms.
Clinicians can catch these changes earlier when patients or mobile teams document each visit in the field with WoundScribe On Wheels for mobile providers, and trend visual changes across visits with a healing dashboard. For the full structured program, see diabetic foot care.