Napping in the car

[morpheus1958]

Thanks DanGagner, S.L. Ping Beauty, HalfAsleep, SleepRider, SarcasticDave94 for your comments, appreciate it.
S.L. Ping Beauty - I will look more into GERD.

[morpheus1958]

I looked up on GERD. I don't have burning feeling, I don't have sensation of food/liquid coming up from tummy.
But I have a feeling that you get when you try to drink water while laughing, and how one starts coughing because some drops went into airway.

[S.L. Ping Beauty]

I do not get the typical burning either... it is only mild regurgitation that causes me to cough. Any OTC omeprazole for my mild condition helped me. I only mentioned the possibility was in perhaps a scenario where you might be napping after eating (is your napping part of your lunch break?) Eating can gereally cause GERD symptoms in some folks.

Hopefully you do not have the GERD, but was just tossing out the possibility as a question to ask your doctor. Hopefully you can get the mystery solved.

Be well, my friend and Merry Christmas.

[HalfAsleep]

I can totally see this happening after napping in the car! Now that I think about it, I do it a lot...

Have you considered that it might be post nasal drip? And that the drip got triggered by lack of air/dust/sunshine?

The drip I get is from post nasal drip. And yes, it can wake me up if I'm dozing. I think if I were to try and minimize it, I would spritz each nostril a couple of times with Simply Saline right before I did the nap.... This thins the drip.

[Sleeprider]

As I mentioned before, and reinforced by HalfAsleep, post-nasal drip and obstructive apnea seem to go hand in hand.

Post-nasal drip (PND, also termed upper airway cough syndrome, UACS, or post nasal drip syndrome, PNDS) occurs when excessive mucusis produced by the nasal mucosa. The excess mucus accumulates in the throat or back of the nose. It is caused by rhinitis, sinusitis, gastroesophageal reflux disease (GERD), or by a disorder of swallowing (such as an esophageal motility disorder). It is frequently caused by an allergy, which may be seasonal or persistent throughout the year.[medical citation needed]

However, other researchers argue that mucus dripping down the back of the throat from the nasal cavity is a normal physiologic process that occurs in healthy individuals.[1] Post-nasal drip has been challenged as a syndrome due to a lack of an accepted definition, pathologic tissue changes, and available biochemical tests.[1]

I don't know how to explain it, but I get very disrupted napping without CPAP, and this is part of it.  Yours seems more mild.

[morpheus1958]

Thanks S.L. Ping Beauty, napping is not after lunch, I napped at around 5pm and lunch at around 12 noon. 

Also I encounter this issue irrespective of time of the day, so it is not triggered by sunlight.

As HalfAsleep mentioned it seems very much like "Post nasal drip", I remember now when as a child my mom put some medicine through my nose, I got the exact same feeling, as if something is dripping at the back of my upper throat, this is the same sensation.

[morpheus1958]

Thanks Sleeprider, it is interesting that Sleep apnea and PND are friends who like to hang out together.

BTW, I don't get this issue when I can sleeping on a flat surface, 
I suspect that position/angle of my head while I sleep in my car has something to do with this. I will try to change that and try it out.

[Sleeprider]

I have attempted to sleep in my car on cross-country trips of several days duration, and it's futile. Worse on a motorcycle! I am the only one that can sleep in the middle of the Nevada desert and thanks to sleep apnea, get no quiet. I eventually learned to plug a CPAP into the accessory slot, but soon found that a hotel room was even better.

I have spent years learning this stuff, and there I gave you my best advise in one paragraph....get a room.

[SarcasticDave94]

This sleeping in the car thing gave me the flashback to when I was a tractor trailer driver. Feeling tired, I'd pulled into a Lowe's parking lot next to the Sheetz store where I was planning on getting a coffee. I parked safely and fell asleep instantly. Literally. Behind the wheel. And then I woke up a few seconds/minutes later. Still behind the wheel. I SLAMMED on the brakes thinking I was driving and had fallen asleep. Sheetz sold me the biggest, strongest coffee they had!

[HalfAsleep]

The thing about napping in the car (especially while near the open window) is that you are likely to be napping where vehicles put out fumes/dust/grime. You would not normally be likely to sleep under those conditions for the night. So the problem might not exactly be the angle, but might reflect where you've parked.