A bladder spasm occurs when the bladder muscle squeezes suddenly without warning, causing an urgent need to release urine. A bladder spasm is referred to medically as a contraction of the detrusor muscle. The spasm can be so severe as to cause the leakage of urine (incontinence), which is characteristic of the condition urge incontinence, or overactive bladder. Sometimes, a bladder spasm is associated with severe cramping, burning, or pain. Bladder spasms can occur in people of any age. They are a common cause of daytime incontinence in children. They can be related to medical conditions that interfere with the function of the nervous system or may be related to infections or damage to the bladder itself. Certain medications and foods are also irritating to the bladder and may cause bladder spasms.