muscle spasm
"I take 20mg every night to help with my muscle spasms associated with Fibromyalgia. It helps to relax your muscles while you are sleeping so that they are not painful when you get out of bed in the morning. I find that the dose at night before I go to sleep helps to set up a pain-free day. (The Flexeril dose does not start at 20mg. A tolerance to the medicine is needed to take that dose.)"