抽搐，俗称抽筋，人类身体肌肉系统常见的收缩现象。

发作时会使得受伤者感觉疼痛或受到极大压力。常常是因为从静止状态直接转做剧烈运动而导致的。人身体的肌肉是能收缩的，带弹性的，在静止状态下肌肉会在某种状态下保持着，如果突然改变成运动状态，那幺肌肉也必须突然的改变状态，从收缩变放松，或放松变收缩。这时常会导致人体肌肉虽然接收到脑传出做运动的信号，但一时却反应不过来，产生痉挛（肌肉自动收缩），也就是肌肉“不听使唤”。这时候，肌肉触摸上去会感觉紧张且发硬，还有可能会发现肌肉外表变形。发作后如果受伤者停止运动，会持续5至10分钟便会自然地恢复正常。但是如果10分钟后依然还是没有恢复肌肉在静止状态下的原状，很有可能有其他的更严重的潜在病症，需要及时去医院做检查。

A cramp is a sudden, and involuntary muscle contraction or over-shortening; while generally temporary and non-damaging, they can cause mild-to-excruciating pain, and a paralysis-like immobility of the affected muscle(s). Onset is usually sudden, and it resolves on its own over a period of several seconds, minutes, or hours. Cramps may occur in a skeletal muscle or smooth muscle. Skeletal muscle cramps may be caused by muscle fatigue or a lack of electrolytes (e.g., low sodium, low potassium, or low magnesium). Cramps of smooth muscle may be due to menstruation or gastroenteritis.