muscle spasm
"I was prescribed this about 2 years ago. I  have numbness and pain at night in my arm's that keep waking me up. Lots of tension headaches muscle pain and spasms during the  day. I took 1 pill at night and 1 half during the day and it worked great. But I started to get severe redness and heat in my face. Stopped Flexeril and it went away. Only take if absolutely necessary and not more then 2 days back to back. Redness comes back."