Cough cough cough

[user1482573375]

DP has had cough for 10 weeks. Saw Doctor after 3 weeks said nasal drip, given steroid spray. After 6 weeks sent for Xray, that was normal according to receptionist. Cough still here.
Should he go back to doctor?
Worried he's got something like cancer that Xray missed.
Cough was gone by 80%, but now reemerging.

Or has anyone else had a cough like this, he gets a bad cough this time of year, every year. Any remedies, getting fed up with it.

10 months here and they have no idea what it is .. after much Googling i am going for "post nasal drip". Only test I have left to do is for lung cancer but had clear x-ray so probably isn't that. We've gotten used to it and sleep round it now but its a pain