Why Do You Have to Pee When You're Nervous?

If you get the urge to pee when you're nervous, you're not alone.

It's common to feel the need to void your bladder when you're feeling tense, said Dr. Tom Chi, an associate professor of urology at the University of California, San Francisco.

"When in doubt, just do what your body says, and go to the bathroom — you'll probably be OK," Chi told Live Science. [Why Does Asparagus Make Your Pee Smell Funny?]

In a typical situation, when you're not feeling nervous or anxious, the bladder is relaxed as it fills with urine from the kidneys. In contrast, the bladder's external sphincter is tightly closed to make sure that urine doesn't leak out, Chi said.

A healthy bladder can hold up to 2 cups (16 fluid ounces) of urine. Once the muscular sac is full, "the bladder sends a signal through the spine up to the brain that says, 'OK, I'm full; I got to go,'" Chi said. Once this signal is received and the person is ready, the bladder contracts, and the external sphincter muscle relaxes, letting a stream of pee flow.

Doctors aren't entirely sure why people tend feel the call of nature during times of anxiety, largely because the need to pee is controlled by many factors, including the nerves along the spinal cord, the brain and your emotions. But researchers have two good guesses for why this phenomenon happens, Chi said.

One idea is that when you're anxious or nervous, your body goes into fight-or-flight mode. This tense, adrenaline-filled response may stimulate the need to relieve yourself. The fight-or-flight response may also increase the kidneys' production of urine, Chi said.

The reasons linking this response to the need to void aren't fully understood. But it's thought that "under stress, the [central nervous] system is activated to operate at a higher level of sensitivity, meaning that it takes less to activate the reflex," Dr. Alan Wein, a professor of urology at Penn Medicine at the University of Pennsylvania, told Live Science.

The other idea is that when you're nervous, your muscles tense up, "and one of those muscles may be the bladder," Chi said. "When that happens, it makes you want to pee."

If you're nervous and feel the need to pee but you don't have easy access to a bathroom, Chi recommended distracting yourself or doing meditation exercises to relax your mind and muscles.

Original article on Live Science.