26th June 2023

Types of urinary incontinence

Evaluation of urinary incontinence is based on clinical history, including the situation in which incontinence occurs, bowel and bladder habits, symptoms, lifestyle behaviours, and past medical history. Investigations include urine culture, blood tests including renal and thyroid function, and glucose tests. Further tests may include postvoid residual volumes, renal ultrasound, and urodynamic studies. Renal ultrasound can be used to rule out hydronephrosis and kidney stones, and postvoid residual volumes can monitor urinary retention secondary to obstruction or neurogenic bladder.

Urge Incontinence

Urge incontinence is a subset of overactive bladder (OAB). Overactive bladder is defined as urinary urgency with or without incontinence, accompanied by increased frequency and nocturia. Risk factors include:

• Systemic neurological conditions such as Parkinson’s disease, multiple sclerosis, or injury to pelvic or spinal nerves
• Comorbidities such as obesity, type 2 diabetes, and chronic urinary tract infection can increase urgency symptoms
• Drugs such as parasympathomimetics, antidepressants, and hormone replacement

The first step in management is behavioural interventions such as prompted voiding, scheduling toileting, bladder training and pelvic muscle exercises. Following this, medical therapy includes alpha-1 blockers and anti-muscarinic acetylcholine drugs such as darifenacin.

Stress Incontinence

Stress incontinence is defined as involuntary leakage on effort or exertion, for example, on sneezing or coughing. Risk factors include:

• Increasing age
• Pregnancy and vaginal delivery — muscles and connective tissue can be weakened during delivery, and damage may occur to pudendal and pelvic nerves.
• Obesity — due to pressure on pelvic tissues and stretching and weakening of muscles and nerves from excess weight
• A deficiency in supporting tissues, for example:
  • Prolapse — not a cause of stress urinary incontinence but may be caused by the same underlying deficiency of supporting tissues
  • Hysterectomy — surgery may damage the pelvic floor muscles
  • Lack of oestrogen at the menopause — oestrogens keep tissues that influence normal pressure transmission in the urethra healthy and maintain urethral secretions that help to create a ‘seal’.
• Smoking — smoking is associated with chronic cough, which may contribute to stress urinary incontinence.
• Drugs — for example, angiotensin-converting enzyme (ACE) inhibitors (can cause cough and worsen stress incontinence)

Managing contributing factors, such as weight loss, smoking cessation and reducing oral liquid intake, can help improve symptoms. Other management options include supervised pelvic floor muscle training, or surgical options such as colposuspension, sling surgery or vaginal mesh surgery. If surgical options are not viable, selective serotonin inhibitors can be utilised as pharmacotherapy.

Neurogenic Bladder

Neurogenic bladder refers to disorders of the urinary bladder relating to dysfunction of the central nervous or peripheral nervous system, affecting the nerves involved in control of urination. This can present as urge incontinence, urinary frequency, and urinary retention. Causes include injury to the spinal cord, multiple sclerosis, stroke, and neurodegenerative diseases. Children with spina bifida often have urethral sphincter dyssynergia which leads to incomplete bladder emptying or incontinence. This can be worsened with superadded frequent UTI bs leading to reflux causing upper tract dilatation which in turn can cause chronic kidney disease (CKD).