There are a number of different causes of bladder spasms. The cramping pain could be due to something as simple as your diet or a medication that you are taking, or it could be associated with changes in blood supply and function of the nerves controlling the bladder. However, bladder spasms may be the result of an infection or a recent surgery, or they may occur if you have nerve or muscle damage. So it's important to see a doctor to determine the cause. In some cases, your doctor may not be able to identify the cause. When this happens, the condition is called idiopathic bladder spasms.

Conditions that may lead to urethral spasm:
1. Urinary tract infection (UTI): Bladder pain and burning are a common symptom of a UTI.
2. Interstitial cystitis: This condition refers to bladder and urinary pain that is not due to other causes, such as a urinary tract infection. Pain is recurring and often severe.
3. Catheter use: A catheter is a thin tube used to drain urine from the body, often after surgery. It is placed into the urethra and up into your bladder. Bladder spasms are a common and sometimes distressing complication of catheter usage.

Nervous system disorders and injury that can cause bladder spasms include:
1. Herpes zoster infection that affects the nerves in the sacrum
2. Multiple system atrophy (Shy-Drager syndrome)
3. Stroke that has caused brain damage
4. Parkinson's disease
5. Spinal cord injury
6. Brain tumor
7. Cerebral palsy
8. Multiple sclerosis