Development of nocturia is a common change in voiding patterns that occur with advancing age. This can lead to negative outcomes on sleep quality and other aspects of quality of life. As age increases, the circadian rhythm of urine production shifts, and there is a greater volume of total urine production at night compared to during the day (Miller 2000). Nakamura and colleagues demonstrated a significant increase in urinary frequency between midnight and 6 am in elderly patients (Nakamura et al. 1996). A cohort study of 935 otherwise healthy men demonstrated that those over 63 years of age had an average voided volume of 200 mL and had around 6 voids each day with an average of one each night (Huang Foen Chung and van Mastrigt 2009). This was in contrast to the comparison group of younger men, aged 38–62 years, who typically voided larger volumes and had between 5.5 and 6.0 voids daily, with 0–1 voids each night. Every participant had International Prostate Symptom Scores less than 10, suggesting mild lower urinary tract symptoms and a minimal contribution from prostatic hyperplasia. Clinical judgment must play a role in defining urinary frequency and bothersome nocturia for each patient, as confounding factors such as medications and regional variations in diet and activity preclude gross generalization of urinary habits in all older people.

Although it may seem obvious that a thorough history and physical examination is necessary in delineating the etiology of a geriatric patient’s urinary dysfunction, these patients often require patience and coaching from their providers. Many receive clinical care from others or may have memory issues, comorbidities, or polypharmacy which could mask symptoms. The use of directed questions and prompting may be necessary. Visser and colleagues found that 64 % of women aged 55 years or older with urinary incontinence had not discussed their symptoms with their primary care provider (Visser et al. 2012). Urinary retention in the older patients is frequently multifactorial. Detrusor underactivity can be the result of chronic medical conditions such as Parkinson’s disease, stroke, spinal cord trauma, or poorly controlled diabetes with subsequent neurogenic or myogenic dysfunction (Kebapci et al. 2007; Thorne and Geraci 2009).

Symptoms associated with urinary retention include weakened urinary stream, urinary tract infection, inability to urinate, or worsened constipation (Tan et al. 2001). Patients with complaints of recurrent urinary tract infections should be evaluated for the possibility of underlying urinary retention and incomplete bladder emptying. A voiding diary can be a useful adjunct measure, especially if the patient or caregivers can perform measurement of urine output and clean intermittent catheterization to measure postvoid volumes. More structured urodynamic evaluation may be useful to provide objective measures of bladder function in select patients. This can be particularly helpful in guiding treatment decisions, especially if prior treatments have been unsuccessful.

Elevated postvoid residual volumes can be measured either by catheterization or bladder ultrasound. In the geriatric population, intermittent catheterization can be invasive and uncomfortable, with the potential risk of introducing bacteria into the bladder. Ultrasound technology offers the benefit of being noninvasive and has been shown to be reasonably accurate and with reproducible results in the hands of trained staff (Ouslander et al. 1994; Borrie et al. 2001). However, the device is somewhat expensive and not every clinical setting will have access to this equipment. Currently, there is no clear consensus on what constitutes an abnormal PVR, particularly among geriatric patients. Volumes between 50 and 300 mL have all been used to define retention, and practitioners need to use these volumes as guidelines rather than absolute targets. In most settings, a volume of 100–150 mL may be a reasonable compromise.

The condition known as DHIC, or detrusor hyperactivity with impaired contractility, was first characterized by Resnick and Yalla in 1987 in a series of women with both urge urinary incontinence and elevated postvoid residual volumes associated with poor bladder contractility (Resnick and Yalla 1987). Pharmacological management of urinary urgency and urgency incontinence is usually contraindicated in patients with elevated postvoid residual volumes. This can make treatment of the condition more challenging and may also require the use of clean intermittent catheterization to regularly empty the bladder. Although bladder outlet obstruction has been shown in animal models to contribute to detrusor underactivity, men with DHIC or even pure detrusor underactivity may have their symptoms incorrectly attributed to purely BPH alone and undergo unnecessary surgical procedures to relieve obstruction. Thomas and colleagues demonstrated that men who underwent transurethral resection of the prostate with underlying detrusor underactivity experienced no significant symptomatic or urodynamic changes, compared to men with bladder outlet obstruction alone (Thomas et al. 2004). Because of this, urodynamic studies may be particularly useful to differentiate between these types of patients.

In a population of 181 men and women aged 70 years or older with LUTS, Abarbanel et al. found that 48 % of the men had impaired detrusor contractility, and of them, 67 % had associated detrusor hyperactivity (Abarbanel and Marcus 2007). Only 10 % had isolated bladder outlet obstruction, and 45 % had pure detrusor hyperactivity. Among the women in this study, impaired contractility was seen in 12 %, and half of these patients also had detrusor hyperactivity. Overall, only 32 % had pure detrusor overactivity. Regardless of gender, history of urinary retention or presence of indwelling catheter predicted those with detrusor underactivity. Because treatment of urgency urinary incontinence will paradoxically worsen the symptoms of patients with DHIC, older adults presenting with these symptoms should be carefully evaluated for underlying detrusor underactivity prior to initiation of pharmacologic or other therapy.

Approximately 80 % of people aged 65 years and older take an average of 2.9 prescription medications daily (American Geriatrics Society 2012 Beers Criteria Update Expert Panel 2012). In the geriatric population, critical attention must be paid to the potential adverse effects of medications, including drug-drug interactions, some of which may cause voiding dysfunction. Geriatric patients experience alterations in both pharmacokinetics and pharmacodynamics due to physiological alterations associated with the normal aging process. Absorption of medications may be slower, drug distribution may be altered by decreased lean muscle mass and increased adipose tissue, and both renal and hepatic metabolism may be diminished with advancing age (Willlams 2002). In order to help guide practitioners through these risks, the American Geriatrics Society recently published the fourth updated version of the Beers Criteria (American Geriatrics Society 2012 Beers Criteria Update Expert Panel 2012). These evidence-based recommendations can be useful in helping to avoid potentially inappropriate medications in this more vulnerable older population.

Medications with anticholinergic effects must be used with great caution due to potential worsening of urinary retention and constipation. One study of 738,004 men aged 20–84 years who were prescribed anticholinergic medications for lower urinary tract symptoms found a relative risk of acute urinary retention of 8.3 (95 %) within the first 30 days of therapy, although the relative risk decreased to 2.0 (95 %) with longer duration of use (Martin-Merino et al. 2009). Older patients are also more sensitive to the risk of dry mouth and xerostomia which can influence swallowing function and increase the risk of gingivitis and other tooth and gum disease. Other potential side effects of these medications include increased confusion and delirium and potential orthostatic hypotension. Glaucoma is common in older adults, and the anticholinergic medications are contraindicated in patients with a history of narrow angle, sometimes called closed angle glaucoma.

Opiate analgesics tend to increase external urethral sphincter tone and decrease the sensation of bladder fullness. They can also decrease overall mobility and increase risk for delirium in some older adults. The risk of urinary retention associated with these medications appears to be higher with the longer-acting pain medication (Darrah et al. 2009). Similarly, general anesthetics promote smooth muscle relaxation and can contribute to postoperative urinary retention. The risk is even higher in those patients treated with epidural pain management, with retention rates up to 23 % in some studies (Darrah et al. 2009).