Micturition

Definition

Micturition (urination, voiding) is the process of discharging urine from the bladder. It involves coordinated detrusor muscle contraction and sphincter relaxation under parasympathetic control.

Normal Patterns

• Adult: 1,500 to 2,000 mL urine output per day
• 4 to 6 voids per day of 200 to 400 mL each
• No pain, urgency, hesitancy, or incontinence

Assessment of Urinary Elimination

• Frequency, volume, color, clarity, odor
• Dysuria, urgency, hesitancy, incomplete emptying
• Postvoid residual (PVR) by bladder scanner or catheterization

Common Alterations

• Anuria: less than 100 mL/day
• Oliguria: less than 400 mL/day
• Polyuria: greater than 3,000 mL/day
• Nocturia: frequent nighttime voiding
• Incontinence (stress, urge, overflow, functional)

NCLEX Relevance

Urinary alterations are key clinical cues. Bladder scanner preferred over catheter for PVR.