A baby's bladder holds about 30-60 mL, growing to around 100-200 mL by age 5, and reaching typical adult capacity of 300-400 mL (or more, up to 700 mL) by adolescence, with formulas like (age + 1) x 30 mL estimating capacity for children up to 12 years old. Adult capacity varies but generally settles at 400-600 mL, with some holding up to 2 liters, though needing to void more frequently with age.
The normal expected bladder volume until the age of 12 is calculated as (age + 1) × 30 ml, with 400 ml expected for those over 12. The average daily bladder volume is usually 65-150% of the expected capacity.
Contraction of smooth muscle is necessary during bladder emptying as it aids in propelling urine expulsion. However, amlodipine may attenuate this contraction, leading to incomplete bladder emptying and consequent urinary retention.
The "21-second pee rule" comes from a scientific study showing most mammals over about 3 kg (6.6 lbs) empty their bladders in roughly 21 seconds, a phenomenon explained by physics where longer, wider urethras in larger animals use gravity to maintain a similar flow rate to smaller ones, and it serves as a loose benchmark for human bladder health; significantly shorter or longer times can signal issues like overactive bladder or holding it too long.
A urodynamic study of 436 men and women showed that, in both sexes, postvoid residual volume increased and peak flow rate decreased with age. Bladder capacity also diminished with aging. However, maximum detrusor pressure and detrusor pressure at peak flow rate did not correlate with age.
For most people, the normal number of times to urinate per day is between 6 – 7 in a 24 hour period. Between 4 and 10 times a day can also be normal if that person is healthy and happy with the number of times they visit the toilet.
Typically, people lose kidney function by about 1% a year after age 50. If you have a decline in kidney function faster than the regular rate associated with aging, you are in trouble. There are things you can do or avoid to forestall further renal decline, particularly in the realm of lifestyle modifications.
A moderate urge normally occurs after about 300 ml is in the bladder. When someone is in a situation where they cannot reach the bathroom easily, often bladder can store as much as 1 liter (1,000 ml) but with some obvious discomfort.
Normal frequency (how many times you urinate) during waking hours for adults is 5-8 times (around every 3-4 hours). During sleeping hours, waking once to urinate can be normal for people under the age of 65. As a person ages, the bladder capacity becomes a little less.
Common side effects
5 of the worst blood pressure medications
Medications. Certain medications can cause urinary retention. Drugs like antihistamines (Benadryl®), antispasmodics (like Detrol®), opiates (like Vicodin®) and tricyclic antidepressants (like Elavil®) can change the way your bladder muscle works.
Urinary bladder and urethra
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.
Some medications such as antihypertensives, sedatives and muscle relaxants can cause urinary incontinence by directly affecting the smooth muscle tissue of the bladder. These drugs can relax the detrusor muscle which is responsible for contracting and expelling urine leading to difficulty controlling urine flow.
Key Takeaways
If you feel the need to urinate more often, especially at night, this can be a sign of kidney disease. When the kidney's filters are damaged, it can cause an increase in the urge to urinate. Sometimes this can also be a sign of a urinary infection or enlarged prostate in men.
Practice pelvic floor exercises, also known as Kegel exercises. Squeeze the pelvic floor muscles as though trying to stop the flow of urine for three seconds. Relax for a count of three and repeat several times. Do a set of these exercises three or four times a day.
Medicine for nocturia
A low-dose version of a medicine called desmopressin may be used to treat nocturia, which is the frequent need to get up during the night to urinate, by helping to reduce the amount of urine produced by the kidneys.
Leaning forward and rocking may promote urination. After you have finished passing urine, squeeze the pelvic floor muscle and then relax it, to try and completely empty. Tapping over the bladder may assist in triggering a contraction in some people.
If you drink 8 ounces of water, it will generally be in your bladder within 20 minutes. So, it's a good idea to plan your restroom breaks if your bladder doesn't give you the warning signal. Additionally, there's no health benefit to consuming large volumes of water. Drinking more than 12 ounces at once is excessive.
There are several reasons why your bladder function changes with age. The most significant change is that the bladder becomes less elastic. That means it's no longer capable of holding as much urine as it used to. The loss of elasticity can also affect how well the bladder can empty when you pee.
Diabetes and high blood pressure are the top culprits damaging kidneys most, as they harm the delicate filtering blood vessels, leading to chronic kidney disease (CKD) and failure; other major factors include smoking, obesity, dehydration, poor diet (high sugar/salt/red meat), certain medications (NSAIDs), lack of sleep, and genetic conditions. These factors create a cycle where damaged kidneys worsen blood pressure, further damaging them.
It may seem like you have to pee every hour (or maybe every other hour). Depending on who you ask, this might not be viewed as a problem but merely a symptom of aging. And it's true: A host of changes happen to your body as you get older, including bladder issues.
Symptoms can include: