Chilblains (dòng chuāng) is a painful, itchy skin condition caused by repeated exposure to cold—but not freezing—temperatures, typically affecting fingers, toes, ears, or nose. The word combines 冻 (dòng), meaning 'to freeze' or 'cold injury', and 疮 (chuāng), meaning 'sore' or 'ulcer'. Together, they literally mean 'cold sore'—not to be confused with the viral herpes sore, but rather an inflammatory reaction to cold dampness.

This condition is common in humid, chilly climates where heating is limited, especially among children and elderly people with poor circulation. In traditional Chinese medicine, it’s often linked to 'deficient yang qi' and treated with warming herbs or external applications. Modern prevention focuses on keeping extremities dry and well insulated during cold weather.