This is an interesting (as well as alarming) situation for me.

I've never dealt with anything like this before, so bear with me. I have an adult male ball python (age unknown, was bought as a rescue adult). Big boy at about (almost) 5 feet long and weighing around 4 lbs.

Last night I went to turn off his light and I noticed that his head looked really weird. His jaw muscles (and only his jaw muscles) were quite swollen/enlarged and he had his mouth slightly open. The moment I went to touch him, he started hacking and coughing. Mouth completely open, with full, and quite loud heaves. At one point these heaves were becoming full-bodied and he was moving around a lot to make these heaves. They sounded almost rattle-y, not necessarily wet. The last heave that he did he opened his mouth completely and extended his glottis and did one more big one, which is when I noticed that there was either a) blood in the back of his mouth or b) the back of his mouth/throat area is severely inflamed.

Because I did not have enough time to look nor a good angle, I can't confirm or deny whether it was blood or not.

After this he went back to normal. Mouth was closed evenly, there was no more puffyness to his head or anything like that. So I will throw a few things out there:

1. After this all, his tongue was flicking normally and he went back to trying to explore around his cage, but it was kind of sluggish and lethargic.
2. There is no visible swelling anywhere from what I can see.
3. No fluids or anything came out of him from this heaving.
4. He last ate about 12 days ago, he's on med. rats. He was supposed to eat yesterday but I obviously have concerns now about feeding him until I know what's going on.
5. Physically he looks fine. He's well muscled and is hydrated and all of that jazz.
6. Since I know people are going to ask, he has a basking spot of about 90-91 degrees. Main area of the cage is about 85-88 degrees and the cooler end is 81. Ambient air temps are around 80-82. He's being heated via radiant heat panel in an animalplastics t8. He's on newspaper.

This only just happened last night around 10:30 PM. There are no emergency vets around here and the herp vet near me will not be in office until Friday.

If anyone a) has any insight as to what might have happened or b) has any advice on what to do/look out for before I can get him to the vet, it'd be greatly appreciated!