My mom is having severe muscle spasms all over her body what causes them and what relief can she get?

There are a few: Causes, including severe dehydration or deficits in certain things like potassium or magnesium, which can be life threatening. Is she on a statin? That can cause it as well. If she is having other symptoms, this could be something emotional or neurological as well. Hard to tell without a physical exam and labs. If they are acute in nature, i would recommend seeing a physician sooner than later.