A common cold (and broadly, respiratory illnesses like flu) — an illness affecting the respiratory system with symptoms such as a sore throat, runny nose, or fever.
昨夜からのどが痛くて、どうやら風邪をひいたらしい。
My throat has been sore since last night; it seems I caught a cold.
冬は風邪を引きやすいので手洗いをしっかりしよう。
You catch colds more easily in winter, so wash your hands thoroughly.
風邪の症状がひどければ病院で診てもらってください。
If your cold symptoms are severe, please see a doctor at a clinic.