The document discusses polydipsia (excessive thirst) and postprandial somnolence (sleepiness after eating). Polydipsia can be caused by physical diseases like diabetes that result in high blood sugar, or by losing fluids from vomiting, diarrhea or sweating. It causes symptoms like blurred vision, confusion and fatigue. Postprandial somnolence is a normal feeling of drowsiness after eating, caused by the body slowing digestion and an insulin spike making the brain produce hormones that induce sleepiness. Eating smaller, more frequent meals and being active after eating can help prevent excessive post-meal sleepiness.