From the Fortean Times, a piece on nightmare death syndrome, locally known as bangungut.
“A man who goes to bed fit and healthy is heard to cry out in his sleep, and the next morning is found dead. The same scene is repeated again and again. The doctors cannot find any physical cause for the mysterious deaths, but people mutter darkly about dÃ¦monic beings and deadly dreams. The 11 victims were all Filipino sailors. . .”
A friend of mine swears that twenty years ago he experienced something very similar to bangungut, except that he was awake at the time. He was on vacation in his hometown, and after a heavy lunch of rice, tuyo, and chorizo bilbao, he felt a terrible pain in his midsection. Now this is what generally happens when you eat an entire kaldero of rice with salty fish and lardy sausage, but this pain so extreme he couldn’t breathe. He had all the symptoms of bangungut, only he was conscious.
He was was rushed to the town hospital, where the doctors were ready to open him up to see what was wrong with him. Fortunately, his friend happened to be visiting the hospital at the time. This friend, a veterinarian, had a look at him and declared that he’d seen the same thing happen to horses. His advice was to get a test for serum amylase.
My friend the patient suggested this to his doctor, who said, “Hmm, where’d you hear that?” The patient was too embarrassed to say the advice had come from a vet, so he feebly claimed to have read it somewhere. The test for amylase was done, and my friend was found to be suffering from “reverse peristalsis of the pancreatic duct”. Something about his stomach being so full of rice swollen with salt that it was putting pressure on his pancreas. So they pumped out his stomach as if he’d OD’d, and he survived his waking bangungut.