There is literally no end to the list of things that can piss off your diaphragm. "There are a ridiculous number of causes," Rachel continues. "The vagus or phrenic nerves, which control the diaphragm, can be irritated by something like multiple sclerosis. Eating too fast can irritate the muscle. Alcohol, hormones, or electrolyte imbalances can impair nerve function. A brain tumor can cause a defect in the nervous system. Anxiety can trigger a stress response, which can lead to hiccups. Underlying medical conditions like pancreatitis or asthma can cause hiccups. Even breathing too fast can trigger a spasm."
"I've been able to narrow down the list of possible causes to fucking anything."
There's at least one cause no one's identified, since doctors have yet to figure out what's causing Rachel's hiccups. "One theory is that the vagus/phrenic nerves are aggravated by my back problems," Rachel says. "Another is that polycystic ovarian syndrome is raising my intercranial pressure (there's too much fluid in my brain and spinal cord), and that's what's irritating the nerves."
That's all well and good, but ask Rachel how much theories have helped her. She'll respond with *hic*.