The bladder can have a mind of its own. Normally, the bladder relaxes as it fills and contracts only when you need to urinate. Bladder spasms can occur when the bladder muscles suddenly contract causing a sudden need to urinate. In some people this can also cause pain.
The symptoms of bladder spasms can be intense, impacting your work, education, and social life. Bladder spasms can occur in overactive bladder, interstitial cystitis, and other conditions.