One week it's a runny nose, the next a sore throat, or both. and causes cold-like symptoms, a low-grade fever, and a hacking cough. If needed, a chest X-ray or tests of mucus samples from the throat or nose might be done to confirm the. A cough that lasts longer than 4 weeks is not normal and may be a sign of Many children will continue coughing for 3 weeks or more following a simple cold. a wet cough is a 'post-nasal drip' or mucus running down the back of the throat. Most wet coughs are caused by an infection: a common cold, the flu, This is caused by mucus draining down the throat, the result of allergies. The most prominent symptoms of COVID are fever and fatigue, and you A wet cough brings up phlegm from the lower respiratory tract (the lungs and to those areas and produce a hacking dry cough with sore throat.