I've had a chesty cough since little, why won't it just go?

[Mumoftwinsandasingleton]

All my life I've had lungs which just seem permanently full of phlegm. I remember describing the pain in my lungs to my headteacher when only 8. I've been to the doctor's every time it gets really bad. They say they hear a "gentle rattle" and that's it's probably just a chest infection. I am then prescribed antibiotics - I feel fully healthy for about 2 weeks and then it all comes back again. Things to note:

• there's a growling sound in my lungs until I cough
• thick green phlegm after every cough
• cough is painful
• really awful taste whenever I cough
• I've never smoked and I eat healthily most of the time.
• natural slim build
• I'm youngish at 31

Any advice would be most welcome. I just want to cough clear forever. I'm the only person I know who always has a cough. Even my mum is healthier than me and never coughs despite years of smoking

Do you live in a really damp area?

Mould? Allergies? Asthma ? Reflux

I can see everyone here has suggested these things tho

It's called clarithromycin. I was given amoxcillan last time. Hopefully it'll clear it. I've been prescribed it for two weeks and only started the course today

I was raised in a highly polluted area but have now moved to a rural area

Have you ever been tested for cystic fibrosis?

I was very similar and think it was from years of being smoked over by parents and grandparents. I have never smoked.

A few years after having not lived with family I felt an improvement. I do still get a lot of coughs and they go straight to the chest.

I thought I may have that after watching a documentary (as a child) about a little girl in hospital who had cystic fibrosis. I don't think it's that though