@kmakm
I had a chronic cough for years leading up to my diagnosis of BC ..... and it has almost gone now! Just the odd cough in the morning (which I think is just gravity .... as you stand up out of bed, mucous in the back of your nose/throat trickles down the throat & you cough it up!)
I had a SHOCKING bout of colds/flu at the end of last year (about 4-5 in a row) leading up to & during my diagnosis .... ending up on antibiotics for most of them!
With us heading towards Spring now .... allergies can be a problem too - so cleaning your sinuses can help - flushing it out. It also keeps your nose hairs 'moist' which is a good thing.
A Neti Pot is good for clearing sinuses - I use one (with filtered or distilled water.) You can get little salt sachets (exact right quantity) and it just takes 1 minute to do both sides. Dr Oz recommends using Baking Soda instead of salt!
http://www.neti.com.auAs @Blondy says - reflux can also cause coughing. Putting a brick under both legs at the TOP of your bed to help reduce this, as the stomach acid can't go uphill - it aggravates the lining of your throat! Once your throat has 'healed' - the cough shouldn't happen. I've just left our bed on the bricks, anyway!