THAT is what it looks like! Sometimes more green crusty around the edges. This looks like an 'immature' one, lol.

I get those too, mine is from a cyst in my throat

Did you get answer,? I've had since nasopharynx surgery at Mayo

Mine looks very similar to this. Have been having this for up to a few weeks now (* see caveat below) in addition to a "sour" sensation at back of throat, in the morning before I clear it. Also noticed blood in snot when I blow my nose in the morning, mostly from the right nostril, but I didn't need to blow my nose this morning as it felt clear after I started using Xlear saline nasal spray yesterday. No cough or other symptoms so I'm assuming it's not lung-related. The theory of post-nasal drip coupled with seasonal dryness makes sense.

* Caveat: The snot in mouth and blood from nostril occurred MOSTLY when I was in NYC, including in my apartment where the humidity is 25%. I was in the UK and Europe for 2 weeks where at least the nasal blood issue largely disappeared, though the throat mucus thing may have still been there but less noticeable. Perhaps although it was cold there, there was maybe more humidity. The theory of postnasal drip and dry air makes sense. Although I've been living in the same place for years and it seems it only started happening this year.

I'm going to keep up the nasal spray at least twice a day and hopefully it eases up. I have reservations using a humidifier because they require a lot of upkeep (refill and cleaning) and I've heard of cases of people getting upper respiratory infections due to mold growth in the humidifier. Which I presume would likely be worse than whatever this is.

Some pics of mine can be found at imgurl at /a/FFQqjqM. The first 4 images are from blowing my nose, and the last 2 are from my throat (last one shows blood).

Other notes: Relatively recent scope, imaging and tests did not show any GI issues (including LPR, acid reflux or GERD, which I asked doc about to make sure they checked for those). Blood tests normal except persistently elevated bilirubin due to Gilbert's Syndrome. Full-body MRI early last year had findings for the sinuses and mastoids (although I recall also having temporary heavy nasal congestion at the time so not sure if I'd get the same results now): "(1) We detected multiple lesions which are consistent with mucous retention cysts. The cysts are located in the right maxillary sinus. Most commonly these are of no concern, unless they become large at which point they cause discomfort. This is a benign finding. If you are asymptomatic, then this finding can be reassessed on your next Prenuvo scan. (2) There is mucosal thickening of the ethmoid air cells and right maxillary sinus. No follow up is needed unless you have symptoms related to this finding." Also relevant: "The remaining paranasal sinuses are clear. The mastoids are clear." "Nasal pharynx: No adverse findings. No worrisome mass is identified."