Coryzas, also known as common cold or head cold, is a viral infection that affects the upper respiratory tract. Some common synonyms for coryzas include rhinitis, nasal congestion, sinusitis, postnasal drip, and runny nose. These terms describe different symptoms of the same condition. Rhinitis refers to the inflammation of the nasal cavity, while nasal congestion refers to the blockage of the nasal passage. Sinusitis is an inflammation of the sinuses, and postnasal drip is the excessive mucus that drips down the throat from the nasal cavity. Runny nose, on the other hand, refers to the flow of mucus from the nasal passage. Understanding these synonyms can help in identifying and treating coryzas effectively.