Urine is produced by the kidneys and stored in the bladder. Bladder function requires a normal urinary tract and depends on intact communication pathways between the nervous system and bladder muscle (detrusor). In many cases, the exact cause of the involuntary contraction associated with overactive bladder (OAB) is unknown. However, there several known factors that can either cause involuntary contraction of the bladder muscle or contribute to improper bladder function and cause symptoms of OAB. These factors include certain medical conditions and medications.
Causes of Involuntary Bladder Contraction
Neurological Conditions
Certain neurological conditions may disrupt signals between the nervous system and the bladder muscle and cause symptoms of OAB.
- Parkinson’s disease
- Multiple sclerosis
- Spinal injury
- Stroke
Nerve Damage or Trauma
Nerve damage or trauma caused by surgery, certain therapies, or trauma to the pelvis or abdomen can cause temporary loss of control of bladder muscles.
Obstructive Conditions
Obstructions such as bladder stones and an enlarged prostate (in men) cam cause symptoms of OAB. An enlarged prostate can weaken the urinary stream and create urinary urgency. It sometimes causes trouble with voiding even when the bladder feels full.
Causes of OAB-Like Symptoms
Other factors and medical conditions can cause symptoms similar to those of OAB.
Medication Side Effects
Water pills prescribed for other diseases can create side effects with OAB-like symptoms. Pills that have caffeine as an active ingredient also have diuretic properties.
Urinary Tract Infections
Infections of the urinary tract can cause increased activity in the muscle of the bladder wall called the detrusor muscle. This creates an overactive bladder and the urge to urinate more.
Medical Conditions
Various disease or conditions can affect the process of filling and releasing fluids from the bladder.
- Diabetes causes nerve damage (diabetic neuropathy), which can affect the nerves that control bladder function and cause urgency and frequency problems
- Kidney disease
- Bladder tumors
Menopause
Menopause causes a sudden drop in the level of estrogen, as well as other drastic changes that a woman’s body goes through when they no longer have monthly menstrual periods. The lower estrogen levels may cause bladder and urethra muscles to weaken. The weakened musculature can cause leakage from sudden urges associated with OAB (urge incontinence) or from sudden movements such as laughing or sneezing (stress incontinence).
Pregnancy
During pregnancy, the uterus expands and can put pressure on the bladder, causing sudden urges or incontinence. Women may also experience incontinence problems after childbirth due to weakened pelvic-floor muscles.
OAB Triggers
OAB can be triggered or made worse by:
- Eating acidic foods, such as tomatoes and citrus fruits
- Excessive drinking of alcohol or caffeinated drinks
- Not drinking enough fluids
- Low fiber intake
- Constipation
- Obesity
