My daughter woke up with a large spot on her foot, and I’m not sure what it is. She’s in a lot of pain and can’t move her foot properly—what could this be?

It makes sense to be concerned when a child suddenly develops a dark, swollen, and painful spot on their foot. It could be something relatively simple like a blood blister caused by friction, pressure, or a minor injury, but the combination of color, swelling, and pain means it shouldn’t be ignored. In some cases it may also be an irritated insect bite, while in others it could point to an infection that needs medical attention. Noticing whether she is avoiding putting weight on the foot or having trouble walking can help indicate how serious it might be.

For now, the safest approach is to protect the area and avoid aggravating it. Don’t try to pop, drain, or cut it, since that can easily lead to infection and make things worse. Keep the foot clean, limit pressure on it, and encourage rest with the foot elevated when possible. A cold compress can help ease discomfort for short periods, and you can ask a pharmacist or doctor about appropriate pain relief for children. If you notice worsening pain, spreading redness, warmth, pus, fever, or increasing difficulty moving the foot, it’s important to seek medical care promptly.