A<unk>  is a sudden involuntary contraction of a muscle, a group of muscles, or a hollow organ such as the bladder. A<unk> odic muscle contraction may be caused by many medical conditions, including dystonia. Most commonly, it is a muscle cramp which is accompanied by a sudden burst of pain. A muscle cramp is usually harmless and ceases after a few minutes. It is typically caused by ion imbalance or muscle overload. There are other causes of involuntary muscle contractions, and some of these may cause a health problem.
Spasm
Orgasm
Irritation
Allodynia
Nosophobia
Pain asymbolia
Hyperesthesia
Irritability