DS has had his fair share of coughs, colds, tummy bugs etc but is mostly a robust active boy with a good appetite. The last few days he has been coughing a lot in the night, with a real heaving sort of cough. Now I have heard one or two other local kids coughing like this in the street and on buses, so I think that it's probably some virus doing the rounds but... OK I have enough medical knowledge just to be able to frighten myself. Can a kid start asthma or any similar horrors at nearly 3 or would there have been signs earlier?