I've caught this off my son. And just like him one day I was fine, next day I woke up ill. I can experience what he is now. Started with a sandpaper feeling at back of throat. Nothing major or painful. But now I've got a cough that hurts my lungs. It's painful when I do cough like my lungs are burning. This has all happened today. Last night I was feeling fine. I've got a bunged up nose and phlegm. Feeling generally unwell. Hoping just a flu. He caught it Monday from his teacher and became ill rapidly.He's still off school but seems better today so he says. He's got a persistent cough though. Is this just the flu?