Symptoms of Diabetic Foot Ulcers

Diabetic foot ulcers don’t appear overnight. They usually develop gradually and often go unnoticed in the early stages, especially in patients with diabetic neuropathy (nerve damage). By the time pain or visible signs show up, the ulcer may already be infected or deep.

Recognizing the early symptoms of diabetic foot ulcers is crucial. The sooner you spot the signs, the sooner you can get treatment and the better your chances of avoiding complications like infection, hospitalization, or even amputation.

Here’s a complete overview of the most common symptoms and warning signs of diabetic foot ulcers that every diabetic patient and caregiver should know.

Symptoms of Diabetic Foot Ulcers

1. Persistent Redness or Discoloration

   One of the first signs of a developing ulcer is redness or dark patches on the foot, especially over pressure points like the ball of the foot, heel, or toes. In people with darker skin, the area may appear more purplish or bluish.

   This discoloration may not be painful but could indicate inflammation, pressure damage, or poor circulation early stages of an ulcer.

2. Swelling in the Foot or Ankle

   Unexplained swelling in the foot, ankle, or leg may be a sign of an underlying ulcer or infection. Swelling can occur due to fluid buildup, poor circulation, or soft tissue damage from repetitive pressure.

   If the swelling doesn’t go away with rest or elevation, it should be checked by a doctor.

3. Warmth Around a Specific Area

   Feeling excessive warmth in one part of the foot could indicate infection or inflammation. Compare it with the other foot if one feels significantly warmer or is red and swollen, it might be the start of an ulcer or abscess forming underneath.

4. Unusual Foot Odor

   A foul or persistent smell coming from the foot or a wound, even after cleaning, is often a sign of infection. This happens when bacteria grow inside the wound, producing pus and tissue breakdown.

   Bad odor should never be ignored; it usually means the ulcer is advanced or infected.

5. Drainage or Pus from a Wound

   Leaking fluid or pus from a wound is one of the clearest signs of a foot ulcer. You may notice:

   • Yellow or green discharge
     
   • Staining on socks
     
   • Moisture inside your shoes
     

   This symptom often points to a deep ulcer or abscess, especially when combined with redness or swelling.

6. Open Sore That Doesn’t Heal

   A non-healing wound, even if small, is a red flag. In diabetic patients, wounds may fail to close due to poor blood flow, infection, or pressure on the area.

   If a cut, blister, or sore remains open for more than 7–10 days, it should be evaluated for ulcer development.

7. Numbness or Tingling in the Feet

   Loss of sensation (neuropathy) is a silent symptom that increases the risk of ulcers. Patients may not feel pain or discomfort, even when a wound has formed.

   If you experience:

   • Tingling or burning sensations
     
   • “Pins and needles”
     
   • Loss of temperature sensitivity
     

   …it means your nerves are affected, and your feet should be examined daily.

8. Pain or Tenderness (In Later Stages)

   Though many ulcers start painlessly, pain can develop if the wound becomes infected, exposes nerves, or reaches deeper tissues or bones. Pain may be:

   • Sharp or throbbing
     
   • Localized to one area
     
   • Worsened by walking or touch
     

   Don’t wait for pain by then, the ulcer is likely in an advanced stage.

9. Hard Callus Over a Red Spot

   Sometimes, ulcers form under thickened skin or calluses, especially on the bottom of the foot. You may notice a hard, yellowish patch with redness underneath. This could be pressing into the skin below, damaging tissue and causing an ulcer to develop under the surface.

10. Fever, Fatigue, or General Weakness

    If a diabetic foot ulcer becomes severely infected, systemic symptoms like fever, chills, fatigue, or increased blood sugar levels may appear. This could signal that the infection is spreading to the bloodstream (sepsis) and needs urgent medical attention.

Conclusion

Diabetic foot ulcers can be silent and painless at first, but they should never be ignored. Early symptoms like swelling, redness, discharge, numbness, or non-healing wounds need prompt medical evaluation. Detecting an ulcer early can lead to simpler treatments, quicker healing, and significantly lower the risk of serious complications.

If you’re living with diabetes, inspect your feet daily, wear proper footwear, and consult a doctor at the first sign of skin breakdown or unusual symptoms. Early action can save your foot and your life.