So what causes your balls to sag?

Let's talk about why your testicles hang off your body in the first place: "They [testicles] like to be a tad big cooler than the rest of your body because thats the ideal temperature for sperm production," Brahmbhatt tells Men's Health. Lax scrotal skin allows your balls to hang lower, away from your body, when your internal temperature rises, like after the gym. When you're in a cold room, testicles shrink up closer to your body for warmth.

With age, skin loses collagen , which causes the dermis to become thin and stretchy. This leads to saggy skin, which can impact your genitals, too. There isn't a magical age that these changes begin to occur, but Brahmbhatt says most of his patients begin to notice a difference in their 60s or 70s.

What's normal, and when are saggy balls a problem?

Of course, some sagging occurs naturally, and there is no "normal" length.

"I dont think anyone has ever done a study to measure how much sag is the average all across America," says Brahmbhatt.

Typically, low-hanging testicles aren't a problem unless it impacts your quality of life. Excessive sagging can make it hard to find clothes, sleep, or even go to the bathroom, he says.

"That stretching can eventually cause pain," he says.

However, sometimes testicles may appear saggy due to medical problems. Inguinal hernias, which happen when tissue pokes through abdominal muscles, can make balls appear saggier. So can cysts. If things look awry, go get checked out.

How do I prevent low-hanging balls?

Your best bet is to follow the basics for maintaining healthy skin, advises Brahmbhatt. This includes not smoking, avoiding sun exposure, limiting alcohol consumption and maintaining a healthy body weight, according to the American Academy of Dermatology.

Some research indicates that diets heavy in sugar may accelerate aging, according to a paper published in the Journal of Clinical and Aesthetic Dermatology .

How do you treat saggy testicles?

You may have heard that certain exercises can prevent balls from sagging. Or that masturbating less can keep balls perky. Neither are true, says Brahmbhatt. And before you turn to Google for all sorts of lotions and potions, there are no medications or creams that work.

In fact, there is only one tried-and-true treatment: Scrotoplasty. "We basically take the extra skin off and try to tighten it up," Brahmbhatt explains. However, this is normally only performed when saggy skin impacts a guy's quality of life.