Why do coughs seem worse in the morning and night?

The subject line pretty much says it all. All that’s left from my fun bought with the dreaded “What’s Going Around Work” is a residual cough. Which doesn’t bother me much except early in the morning or as I go to bed.

So what’s the deal with that? Does the cooler night air exacerbate lung problems? Do you have mucus build up in your lungs as you sleep?

I’ve also found that the supine position of sleeping exacerbates things considerably.

However, sometimes I find that sleeping is not a factor. I’m fighting off a bad UR infection myself (seems to have more punch than a cold). I’ve found that I feel OK during the workday, but get miserable pretty quickly after returning home. Maybe there’s something in the apartment that’s aggravating things (something that wasn’t bothering me 3 weeks ago?).

I’ve noticed that in general, all sickenesses I’ve had, coughs or otherwise, are usually or always worse in the mornings and night.

I’ve always wondered why, hopefully a doc will notice this thread and give the straight dope.

Not a doc even in the slightest, but my SO’s recent trip to the emergency room due to a lovely nighttime asthma attack taught me that the rise and fall of certain hormone levels throughout a 24 hour period plays a large part in various muscle groups contraction/relaxation (they were that vague with me, yes), which can cause more coughing, symptoms of sicknesses, etc.

Googling “asthma nighttime” seems to lend some confirmation to that.

WAG: During the day, you are active. I would guess this produces higher levels of endorphins and adrenaline than just lying in a bed.

I’ve heard in general that your immune system is weaker in the morning; maybe this is why. I’m over my bad cold from last week, but I’m still waking up with a sore throat every day.

True also about smoking cough.

I always wondered why was so severe in the morning.

Is the air in the house too dry? I’ve been using a humidifier this winter and I am amazed that I haven’t once gotten up with a sore throat and don’t have itchy skin.

First, here’s a description from my 8th grade Health teacher, 1961. “Your lungs and your windpipe are lined with tiny hairlike cilia, which are covered in mucus. They try to keep dust and other nasties out of your lungs. When your lungs are tortured by a cold or smoking, there is extra mucus. When you go from vertical to lying down, mucus from one side of your windpipe (trachea) sags across the tube in little stalactites. When they reach the low side, it tickles the cilia there, and you cough.”

“When you’ve been sleeping, and you get up, those gooey strings of mucus fall back to vertical. When they do, they tickle the cilia again, and you cough.”

Since 1961, we have learned a lot about dust mites, which live in your bedsheets and eat your dead skin cells. The dust mite poop is extremely irritating to your breathing system from bedtime to morning. Do you cough in your sleep? How would you know? You’re asleep.

Any doctors on the board care to tackle this one?

Some good plausible answers here. Also informative is that many people, including myself, have nasal-passage deformities (deviated septum, spur, etc.) and hence tend to be mouthbreathers during sleep. The drier air in turn tends to spur the production of mucus, leading to congestion upon awakening and during the period of drifting off to sleep.

Coughing and sometimes just the urge to cough wakes me up.

I’d guess that one’s metabolic rate is lower during sleep, therefore the lungs’ cilia are less active. The cilia aren’t doing their job as effectively, so mucus accumulates resulting in the urge to cough.

Doesn’t look like this has been resolved, and since I’ve wondered about this all my life, I’m going to bump it and hope a doctor might still take a crack at it.