 [ Symptoms ] cortisone injected in my knee yesterday have had a headache ever since is that unusual  also when the doctor used 2 large syringes to drain the fluid he was surprised to find both syringes full of blood is that normal when he injected the cortisone i assume it went into my bloodstream and worry that is what is causing my continual headache  [ Disease ] hi these are some of the side effects form www drugs com less serious clonazepam side effects may include drowsiness dizziness problems with thinking or memory tired feeling muscle weakness loss of balance or coordination slurred speech drooling or dry mouth sore gums runny or stuffy nose loss of appetite nausea diarrhea constipation blurred vision headache and yes it has both of you problems good luck