Imagine that the simple act of urinating for a certain number of seconds could reveal the state of your bladder, alert you to an enlarged prostate or even prevent an infection. Well, this information exists. It is the result of a study conducted in 2014 by the Georgia Institute of Technology. By analyzing the urinary flow of many mammals weighing more than 3 kilos, researchers observed a constant duration: approximately 21 seconds to completely empty the bladder. A rule that works for us too!
Why 21 seconds? A well-oiled mechanism
The Georgia Tech team’s results highlighted a simple physical principle: the longer and wider the urethra, the more gravity increases the output flow. In large mammals as in humans, this mechanism makes it possible to compensate for a greater volume of urine.
Dr Gérald Kierzek confirms this point “In men, urinating for 21 seconds corresponds to a normal bladder evacuating 300 to 400 mL of urine without effort”. An important landmark in medicine.
- Below 10 to 15 seconds, urination raises the possibility of an overactive bladder or low urine volume;
- Beyond 30 seconds, it warns of retention or obstruction, such as an enlarged prostate or a bladder that has become sluggish.
When urinating too quickly becomes an indicator of trouble
An abnormally short time, repeated over days, can signal an imbalance. An overworked bladder, for example, can contract prematurely and shrink over time. “Urinating at the first urge creates a harmful habit. The bladder becomes irritable, which promotes urge incontinence”explains Dr. Kierzek.
Another point of vigilance: excessive hydration. Drinking more than 4 liters of water per day can lead to hyponatremia, which is a lack of sodium in the blood. In this case, one symptom remains to be monitored: very light, even transparent urine, indicates overhydration.
For the expert, certain signs should lead to consultation without delay:
- The need to urinate more than 8 times a day or at night (nocturia);
- Urination lasting less than 15 seconds, frequent and urgent;
- Urine clear as water, with no apparent color.
Holding back too long? Equally real risks
Conversely, waiting too long before urinating (and therefore urinating much longer when the time comes) is not without danger. The main risk lies in the stagnation of urine, which promotes bacterial proliferation. This can lead to repeated cystitis or even more severe kidney infections.
Dr Kierzek details the mechanisms at play:
- Urine retained for too long becomes a breeding ground for urinary infections;
- An overdistended bladder loses muscle tone, leading to chronic retention;
- Excessive concentration of mineral salts increases the risk of kidney stone formation.
Certain signs may also indicate that it is time to consult a urologist:
- Difficulty initiating urination;
- A feeling of incomplete emptying after urinating;
- Dark urine, sometimes odorous.
For the specialist, the rule to remember is simple: do not hold back for more than 3 to 4 hours during the day, except during the night. A good frequency remains between 4 and 7 urinations per day, with light yellow urine, without pain or discomfort.