Men Have Bigger Kidneys But Does That Mean Women Pee More?

We’ve all heard the joke at some point — women take longer in the bathroom because they “pee more.” But is there any truth behind this bathroom stereotype? As it turns out, science is more complex than that, and the answer lies deep within the structure of our kidneys.

Biologically speaking, men generally have larger kidneys than women. But does that mean they produce more urine? Not necessarily.

A recent review of autopsy data has revealed some interesting findings. While men do tend to have physically larger kidneys, researchers aren’t entirely sure if this difference holds up once body size — such as height, weight, or body surface area (BSA) — is taken into account. In other words, just because a man has a bigger kidney doesn’t automatically mean it's more efficient or produces more urine.

Size Doesn’t Always Equal Output

Kidneys are vital organs responsible for filtering waste from the blood and maintaining fluid balance. Each kidney contains roughly a million nephrons — tiny filtering units that help produce urine. The number of nephrons is believed to be associated with kidney size. So, in theory, larger kidneys might have more nephrons and a higher filtering capacity.

However, here's where it gets interesting: When kidney size is adjusted relative to body size, men may not actually have significantly larger kidneys than women. And in clinical settings, women often show better kidney health outcomes over time. Studies suggest that women are less likely to develop or progress to chronic kidney disease (CKD), even though they may report more frequent urination.

So Why Do Women Feel the Urge More Often?

The frequency of urination is influenced by several factors beyond kidney size — including bladder size, hormone levels, fluid intake, and even societal behavior. On average, women have slightly smaller bladders than men, which means they may feel the need to urinate more often, especially when consuming the same amount of fluids.

Hormonal fluctuations during menstruation, pregnancy, or menopause also play a significant role in urinary patterns. Estrogen, for instance, affects the urinary tract and can make women more sensitive to the urge to go.

What It All Means

So, do women pee more than men? It depends. While they may urinate more frequently due to bladder size and hormonal factors, this doesn’t necessarily mean they produce more urine overall. The larger kidneys in men may be more efficient, but that doesn’t equate to more trips to the restroom.

Ultimately, urination is a deeply personal — and variable — experience. If you find yourself making more frequent bathroom visits than usual, regardless of gender, it might be worth discussing with a healthcare provider.

Because when it comes to your health, every drop matters.