A spasm is a sudden, involuntary contraction of a muscle, a group of muscles, or a hollow organ, or a similarly sudden contraction of an orifice. A spasm is usually accompanied by a sudden burst of pain. Spasmodic muscle contraction may be due to a large number of medical conditions, including the dystonias.
By extension, a spasm is also a sudden and temporary burst of energy, activity, or emotion.
A subtype of spasms is colic, an episodic pain due to spasms of smooth muscle in a particular organ (e.g. the bile duct). A characteristic of colic is the sensation of having to move about, and the pain may induce nausea or vomiting if severe.
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