Why cough only at night?

I honest don’t know for sure, but could it be a form of asthma? You should definitely check it out with a doctor.

I know I suffer from coughs after a work out or when I’m out in very cold weather because I have a mild case of it.

edit to add:

I also cough if a fan is blowing in my face when I’m laying down but not when I’m standing up….anyway, you should speak to a doctor to be safe. G’luck. :)

Post nasal drip. His sinuses probably drain into his lungs at night or tickle his throat at night. During the day we are swallowing more saliva that coats the throat, and drip goes i to our stomachs or nose rather than down into our lungs.

If he smokes, as he withdraws off the nicotine at night the cilia in the lungs begins to unparalyze and move crap from the lungs out, which causes coughing. Smoke again, paralyze everything again.

^ Yes, post nasal drip. I am always stuffy in the mornings with my allergy issues and the coughing is the drainage of your sinuses trickling down the back of your throat. Try sleeping slightly elevated.

I went through two years of that and took all kinds of allergy pills. Meanwhile, I was ignoring my acid reflux because it was mild. I was talking to a RN and she asked me if I had acid reflux and I said I did. She suggested I start taking my med regularly every day. In less than 3 days my coughing stopped. She said when you lay down the fumes from the acid will still seep up and irritate your sinuses causing nasal drip. Sitting up can help but who wants to sleep sitting up. After that, I only needed my allergy meds during bad pollen seasons. I’m back to not taking them because many of the acid reflux meds interfere with vitamins for your bones. But I do watch what I eat, and especially for dinner and will take a tums if dinner was a little heavy.
I’ve been sleeping like a baby now for over 2 years.
Hope its an easy fix like mine.

I’m getting in line behind @JLeslie.
For several years I was a heavy smoker and I noticed I had this issue at night. It;s also crops up each time I’ve stopped smoking for about a month and then the lungs heal enough to knock off the sputtering.

Oh yeah, acid reflux, @Pandora is right, that is another possibility.

I used to cough all the time, but even worse at night, I had post nasal drip because of acid reflux.

The acid would evidentally splash up into my larnyx. I take nexium and an allergy pill daily and no more coughing, and got my voice back as a bonus. Acid has less trouble refluxing at night, especially if eating right before bedtime.