What is Overactive Bladder?
Overactive bladder is a medical condition characterized by the inability to control urination. There are 3 main types of urinary incontinence – urge incontinence, stress incontinence, and overflow incontinence.
Urge incontinence is described as going before you reach the toilet – this is usually due to an overactive bladder. Stress incontinence is usually seen in women who have given birth as it is related to pelvic relaxation. Patients lose urinary control when they cough or bear down due to increased intraabdominal pressure. Overflow incontinence occurs when the bladder is full of urine and the urine spills out because it has reached its filling capacity. This usually occurs in men with benign prostatic hyperplasia – the enlarged prostate blocks off or constricts the urethra, making it difficult for urine to exit the bladder.
What Causes Overactive Bladder?
Urinary incontinence is caused by variable factors depending on the type of incontinence. Urge incontinence is usually due to an overactive bladder. Patients have a sudden urge to go and often urinate prior to arriving at their bathroom destination.
Stress incontinence is usually seen in women who have given birth as it is related to pelvic relaxation. When women give birth the anatomy of their urinary and gynecologic tract gets altered, particularly in relation to the stretched pelvic muscles and angle of the urethra. Patients typically experience incontinence when bearing down or with Valsalva.
Overflow incontinence occurs when the bladder is full of urine and the urine spills out because it has reached its filling capacity. This usually occurs in men with benign prostatic hyperplasia. This may also occur in individuals with spinal cord injury in the setting of trauma or multiple sclerosis.
Risk factors for urinary incontinence include:
- Having given birth
- Vaginal birth delivery
- Older age
- Family history
Urinary tract infections may cause urinary frequency and incontinence at times – this is always a consideration in anyone with incontinence.
How Common is Overactive Bladder?
Urinary incontinence is exceedingly common in the United States and responsible for frequent primary care visits. The condition often requires referral to a Urologist if first-line and conservative measures are unsuccessful.
In the United States, weekly urine leakage is reported in about 10% of women and approximately 16% of non-pregnant women age ≥20 years. About 50% of incontinence and 75% of prolapse is caused by pregnancy and childbirth. Some surveys have shown that urinary incontinence is present in about 13% of women age 16-30 years who have never been pregnant.
Signs and Symptoms
Symptoms of urinary incontinence often include:
- Urine leakage
- Urine spillage
- Lack of control of urination
- Urinary frequency
Symptoms may occur more frequency at night time (nocturia) or after certain activities such as bearing down.
Patients with spinal cord injury may be paraplegic and wheelchair bound. They frequently have hyperactive reflexes and reduced lower extremity strength. They may also have reduced rectal tone and are at risk of developing fecal incontinence.
Patients with benign prostatic hyperplasia (BPH) often have an enlarged prostate on rectal examination.
The diagnosis of urinary incontinence is suggested based on symptoms, medical history, and physical examination. Your doctor will usually order a urinalysis and urine culture to evaluate for urinary tract infection – this is a common cause of incontinence, especially in the elderly. In addition, they may obtain a CMP (comprehensive metabolic panel) and CBC (complete blood cell count). They will also usually screen for diabetes.
Occasionally they will recommend obtaining an ultrasound of the bladder before and after urination to assess post-void residual volume. Post-void residual volumes of >200 mL are suggestive of urinary retention. Your doctor may also recommend a CT scan of the abdomen, cystoscopy (to take a look inside the urinary tract), and sometimes urodynamic studies.
Overactive Bladder Medication and Treatment
The first goal is to determine if there is another underlying reversible condition that is contributing to the patient’s symptoms. This may include a urinary tract infection, BPH, or diabetes. These conditions are typically treated before starting any specific therapies for urinary incontinence.
Urinary incontinence is treated with behavior techniques, medications, and occasionally surgery – depending on the type of incontinence.
Women with stress incontinence are trained to perform Kegel exercises – these activities are intended to strengthen the floor muscle of the pelvis, thereby improving incontinence. Patients that do not respond may benefit from placement of a pessary.
Patients with urge incontinence can benefit from bladder training such as timed voiding to keep bladder volumes low and avoid incontinence. Treatment may include medications that relax the bladder muscles such as Ditropan (oxybutynin). Patients that do not respond or cannot tolerate antimuscarinic agents may benefit from Myrbetriq (mirabegron).
The treatment of overflow incontinence involves reversing whatever process that is causing urinary overflow – this may be an enlarged prostate, spinal cord disease, or taking a medication that causes urinary retention. BPH is typically treated with alpha blockers such as Flomax (tamsulosin). Spinal cord disease may require surgical decompression. Certain medications with antimuscarinic activity may cause urinary retention and overflow incontinence – this may be seen with tricyclic antidepressants such as Elavil (amitriptyline). These types of medications may actually be beneficial in patients with urge incontinence.
- Mardon RE, Halim S, Pawlson LG, Haffer SC. Management of urinary incontinence in Medicare managed care beneficiaries: results from the 2004 Medicare Health Outcomes Survey. Arch Intern Med 2006; 166:1128. - https://www.ncbi.nlm.nih.gov/pubmed/16717176
- Coyne KS, Sexton CC, Irwin DE, et al. The impact of overactive bladder, incontinence and other lower urinary tract symptoms on quality of life, work productivity, sexuality and emotional well-being in men and women: results from the EPIC study. BJU Int 2008; 101:1388. - https://www.ncbi.nlm.nih.gov/pubmed/18454794
- Nygaard I. Clinical practice. Idiopathic urgency urinary incontinence. N Engl J Med 2010; 363:1156. - https://www.nejm.org/doi/full/10.1056/nejmcp1003849
The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.