Your veins and arteries are working around the clock to carry blood where it needs to go. But when something goes wrong with those vessels, the body often sends early warning signs.

The tricky part is knowing which symptoms are harmless and which could point to a dangerous condition like a blood clot, arterial blockage or even a stroke.

To help make the distinction clearer, HuffPost asked vascular surgeons and vein specialists to share the symptoms they always take seriously and why you shouldn’t ignore them either.

Swelling and pain in just one leg

“There are a lot of causes for swollen legs, but as a vein specialist, I worry most about a deep vein thrombosis blood clot,” said Dr. Tikva Jacobs, a vascular surgeon at Weill Cornell Medicine and NewYork-Presbyterian Hospital.

“If someone has unilateral (one leg only) swelling and pain that does not go away with elevation, I would want to evaluate that person with an ultrasound to make sure there is no DVT.”

She takes particular note if these symptoms come after a recent flight or long car ride, which increase the risk of developing a blood clot. If a clot breaks free from the leg vein, it can travel to the lungs and cause a life-threatening pulmonary embolism.

“Some of the other causes of swelling that are not as dangerous – like too much salt or being more sedentary usually cause swelling in both legs and often improve with leg elevation,” Jacobs added.

Persistent numbness or tingling in the legs

In addition to sudden swelling in your foot and leg, Society for Vascular Surgery member Dr. Mounir Haurani also recommended paying attention to numbness.

“While your leg falling asleep can occur every once in a while, I would not ignore persistent numbness or tingling in the legs,” said Haurani, who is a surgery professor and chief........

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