Your bladder never empties completely in a perfectly sterile, empty state; a small amount of urine (around 50-100 mL) usually remains, which is normal, but if too much is left (over 200 mL), it's called incomplete emptying or urinary retention, indicating a problem that needs medical attention to prevent complications like infection or kidney damage. Techniques like double voiding (urinating, waiting, then trying again) and proper posture (leaning forward) can help maximize emptying, but persistent issues need a doctor's evaluation.
The bladder never empties completely so some residue is normal. You may find it difficult to start to pass water and even when you have started, the flow is weak and slow. You might find you dribble after you have finished passing water. Perhaps you dribble urine all the time, even without noticing.
Urinary retention is caused by a blockage that partially or fully prevents urine from leaving the bladder or urethra, or a failure of the bladder to squeeze hard enough to expel all of the urine. A number of conditions may cause urinary retention, including: An enlarged prostate (benign prostatic hyperplasia, BPH)
The most common cause of urinary retention is benign prostatic hyperplasia. Other common causes include prostatitis, cystitis, urethritis, and vulvovaginitis; receiving medications in the anticholinergic and alpha-adrenergic agonist classes; and cortical, spinal, or peripheral nerve lesions.
Treatment
Acute urinary retention can be life threatening. If you have any of the other symptoms of urinary retention, such as trouble urinating, frequent urination, or leaking urine, talk with your health care professional about your symptoms and possible treatments. Chronic urinary retention can cause serious health problems.
See a health care professional if you have symptoms of a bladder problem, such as trouble urinating, a loss of bladder control, waking to use the bathroom, pelvic pain, or leaking urine.
The "21-second pee rule" comes from a scientific discovery that most mammals over about 3 kg (like dogs, cows, elephants) empty their bladders in roughly 21 seconds, regardless of their size, due to physics involving urethra length and gravity. For humans, this serves as a loose benchmark: urinating significantly faster (e.g., under 10 seconds) or slower (over 30 seconds) might signal holding it too long or an overactive bladder, though it's not an exact diagnosis.
Drinking a lot of water can cause frequent urination, but so can urinary tract infections (UTIs) and other health conditions like diabetes. Sometimes, you can improve urinary frequency by reducing how much water you drink, scheduling your bathroom breaks, or strengthening your pelvic floor muscles.
Two of the most common causes of chronic urinary retention in women are bladder muscle dysfunction and obstruction.
A bladder ultrasound/scan can be used or measurement residual urine after catheterisation to be certain or not of urine retention. Complications with untreated chronic retention include urinary tract infections, bladder damage, incontinence and chronic kidney failure.
Squeeze your pelvic floor muscles quickly several times (Kegels). Don't fully relax in between Kegels. Relax the rest of your body. Take several deep breaths to help you let go of any tension.
Overactive bladder is not typically cured, but it can be controlled with lifestyle changes, pelvic floor physical therapy, medication, neuromodulation therapies or a combination of treatment options.
If you have an overactive bladder, you may:
Nerves in the bladder wall detect the expansion and send a signal to the brain, letting it know that the bladder is full. The urinary bladder can store up to 500 ml of urine in women and 700 ml in men. People already feel the need to urinate (pee) when their bladder has between 150 and 250 ml of urine in it.
As a result, some individuals drink water and pee more quickly, while others require more time. Healthy individuals will typically absorb water and produce urine in two hours. Therefore, there is no set duration for when water turns into urine; instead, the answer really depends on you.
Over 25 million adult Americans experience temporary or chronic urinary incontinence. This condition can occur at any age, but it is more common in women over the age of 50.
Urodynamic testing checks how well your lower urinary tract stores and releases urine. There are several urodynamic tests you may be asked to do. You may be asked to pass urine into a special funnel to see how much urine you produce and how long it takes.
One of the most common conditions mistaken for a urinary tract infection is a sexually transmitted infection. Chlamydia, gonorrhoea, and trichomoniasis may all cause burning when urinating and increased frequency. Unlike UTIs, STIs might also cause unusual discharge, itching, or pain during sexual activity.
The Red Flag indicators of serious pathology include:
The 5 key warning signs of a bladder infection (Urinary Tract Infection or UTI) are: pain/burning during urination, frequent/urgent need to pee (even with little output), cloudy/bloody/strong-smelling urine, lower belly/pelvic pressure, and feeling like your bladder isn't empty, with fever or back pain signaling a more serious kidney infection, requiring immediate medical attention.
Previous studies have identified certain drugs that may cause urinary retention, including anticholinergic drugs, non-steroidal anti-inflammatory drugs, analgesics, and benzodiazepines.
In appropriate patients, a trained urologist or urogynecology & reconstructive pelvic surgery (URPS) specialist can help. They may offer bladder Botox® (onabotulinumtoxin). Botox® works for the bladder by relaxing the muscle of the bladder wall reducing urinary urgency and urge incontinence.
Fluids that are good for the bladder
Diluted cordial / squash drinks. Diluted fruit juice. Many fruit and herbal teas. Red bush tea (a type of tea that is naturally caffeine free)