The reason people get sick right after the holidays is their already compromised bodies (by way of acidic eating), can not handle even more amounts of acid that comes into the body with our rich dinners.
It is the unflushed acid that makes people have symptoms. My suggestion is instead of heading to the doctor, drink PLENTY of alkaline water (you'll feel symptoms getting less intense within hours ) and eat green vegetables (spinach, kale type).
Good luck.
