You probably cross your legs at least once while you’re having dinner, working at your desk, or pretty much any time you sit down.
Odds are, you don’t even realize you’re doing it — you just sit and cross one leg over the other, like you’ve done for years.
But experts say you might want to rethink that habit: Crossing your legs can actually have some negative health effects. Here’s what you need to know:
1. It Causes Back And Neck Pain
In a perfect world, you’d sit facing forward with both feet planted squarely on the floor. Unfortunately, that rarely happens. Most of us shift our weight around, lean to one side or the other, or, yup, cross our legs.
According to orthopedic physical therapist Vivian Eisenstadt, crossing your legs is just asking for back and neck pain. Sitting with your legs crossed puts your hips in a torqued position, which can lead to the rotation of one of your pelvic bones, she explains. Since your pelvis is the base of support for your spine, it puts unnecessary pressure on your neck and lower and middle back when it’s rotated and unstable. And the longer you sit with your legs crossed, the more pressure you put on your spine, which increases the odds you’ll develop an issue.
“Days and weeks of doing this are one of the main reasons we have back and neck pain, as well as herniated discs,” she tells Yahoo Health.
While it’s unrealistic that you’ll have perfect posture every time you sit down, she recommends sitting with your knees and ankles at 90 degrees with your pelvis balanced whenever possible.
2. It’s (Possibly) Linked To Spider Veins
No one wants spider veins, but they happen — according to the U.S. Department of Health and Human Services, about 55 percent of women and 45 percent of men in the U.S. have them.
The medical community seems to be divided on the link between crossing your legs and spider veins. While some doctors say spider veins are solely caused by genetics, pregnancy, sun exposure, and frequently standing or sitting for long periods of time, others like Hooman Madyoon, MD, a cardiologist at Cedars Sinai Medical Center who specializes in the treatment of venous diseases, tells Yahoo Health that there is an indirect link between the two.
He explains how it works: Crossing your legs increases the pressure on your veins that are responsible for returning blood back to your heart. The pressure of one leg on top of the other impedes your blood flow, which can weaken or damage the veins in your legs. If the veins are damaged or weakened, the blood can leak into them and collect there, causing spider veins or exacerbating existing ones.
3. It Elevates Your Blood Pressure
It’s surprising, but true. Crossing your legs at the knee can temporarily cause your blood pressure to go up.
Here’s why: The blood in your legs has to be pumped back to your heart against gravity, explains Madyoon. That’s already a tough enough task for your body, but when you cross one leg over the other, it increases resistance to the blood flow. As a result, your body has to increase your blood pressure in order to push your blood back up to your heart.
You usually won’t feel any symptoms when your blood pressure goes up, but repeated, drawn-out increases in blood pressure can cause long-term health issues. So, planning to sit for a long period of time? Don’t keep your legs crossed.
4. It Messes With The Nerves In Your Feet
Crossing your legs doesn’t just impact the blood flowing back up to your heart—it affects the veins and nerves in your legs and feet, too.
Crossing your legs at the knee can cause pressure on your peroneal nerve, the major nerve in your leg that passes just below your knee and along the outside of your leg, explains Richard Graves, a podiatrist who specializes in disorders of the lower extremities. This pressure can cause numbness and temporary paralysis of some of the muscles in your foot and leg, preventing you from being able to raise your ankle — what we know as that “pins and needles” sensation.
While the feeling is only temporary, Graves says repeatedly sitting with your legs crossed in the same position can also cause you to develop long-term numbness in your legs from nerve damage.
While he says uncrossing every two to four minutes can help minimize damage, he recommends you ditch the habit entirely: “The best advice is always not to sit with your legs crossed.”