A spasm is a temporary burst of energy, activity, emotion,stress, or anxiety, causing a sudden, involuntary contraction of a muscle, a group of muscles, or a hollow organ, (like the liver) or a sudden contraction of an orifice. They may be experienced with a sudden burst of pain, but are usually harmless, lasting for only for a short period. Spasmodic muscle contractions are also a result of many medical...