| Element | Specific aspect | Rationale |
| History | Review of medical history | Heart failure, diabetes mellitus, hypertension, obstructive sleep apnea, and peripheral edema particularly relevant; narrow angle glaucoma is a contraindication for bladder relaxant therapy |
| Fluid intake | Evaluation for excessive fluid intake (psychogenic polydypsia, health belief) | |
| Medications, especially for diuretics | Late afternoon or evening diuretic use may cause nocturia | |
| Sleep and related conditions | Information about nighttime pain, depression, or insomnia or difficulty with sleep maintenance is important | |
| Dizziness, low blood pressure or orthostasis, or history of accidental falls | May be a contraindication for nonselective alpha-blocker therapy | |
| Dementia or mild cognitive impairment | May be contraindication, use antcholinergic drugs with caution | |
| Physical examination | Supine and orthostatic blood pressure | Particularly if alpha-blocker therapy (for men) is considered |
| Cardiovascular and pulmonary examination | Examination for fluid overload or heart failure | |
| Abdominal examination | Evaluation for suprapubic distention and tenderness (insensitive, but highly specific if found) | |
| Rectal examination | Evaluation for prostate size, rectal masses, or fecal impaction; analysis of resting and volitional contraction (useful for employing behavioral therapy, including urge suppression strategies) | |
| Neurologic examination | Neurologic conditions (spinal cord injury or multiple sclerosis) | |
| Laboratory studies | Urinalysis | Urinary tract pathology, hematuria |
| Electrolyte panel | Evaluation for abnormal renal function; check for glycemic control in patients with diabetes mellitus; examination for low serum sodium (especially for consideration of desmospressin therapy or monitoring) | |
| Frequency volume chart | Nocturnal polyuria, functional bladder capacity, total 24-hour urine output | More accurate description of patient nocturnal urinary patterns |
| Additional studies | Noninvasive uroflowometry (in men) | Low urine flow rate (4 to 15 mL/sec) more suggestive of BPH; very low flow rate (<4 mL/sec) may indicate need for surgical treatment |
| PVR by ultrasound | PVR over 200 mL may be causative of nocturia or may prevent use of a bladder relaxant |
