It's a pretty random occurrence. Sometimes they're unnoticeable, other times they have side effects such as these.
A friend of mine is suffering nosebleeds and minor earaches from it. We both agree it's one of the longest and most painful chinooks to have happened in the past 10 years.
Medication takes the edge off so I feel fine while it's working, but I'm often in bed trying to tolerate the pain and resisting the urge to vomit.