One other thing - a doctor would also be most likely to recommend a trial and error approach to see what successfully relieves the problem.
An ENT could look into your larynx for signs of inflammation from reflux. No other kind of doctor has the equipment. And if the problem only acts up in the middle of hte night the ENT could see nothing wrong.
Allergy tests might yield a hint if that's what the problem is, but treating it will narrow it down faster and far more cheaply if you don't have good insurance.
Dora
Could be allergy. If it is, antihistamine will help, and washing all your bedding in hot water and bleach and drying on high heat will help atleast temporarily (If it helps at all, you need to wrap your mattress in heavy plastic and seal completely with duck tape - and you may need a new mattress as well, and you also need to spring clean your room.)
GERD would also do that, and sometimes that's its only symptom. This is particularly likely if the problem wakes you up relatively early in the night but then doesn't return; you aren't for instance waking up in the morning with a runny nose or runny eyes. Try omeprazole before bed and see if that helps. Could take two of them and a 150 mg ranitidine, also before bed. If that helps, then also raise the head of your bed a foot and a half (may need to put a board under the mattress) and avoid eating for three to four hours before bed.
Dora
Sinus trouble? Post-nasal drip?
Hi, and welcome to the community.
You should see your doctor for an accurate diagnosis.
It sounds like either allergies or reflux triggering the running nose which triggers the coughing. You need to know and treat the cause. Asthma is also a possibility.
God bless.