To check for edema that is not obvious, you can gently press your thumb over the foot, ankle or leg with slow, steady pressure. If you have edema, you will see an indentation where you pressed. You should see a doctor to determine the cause of leg swelling. If both legs are swollen, your doctor will ask about other symptoms and will examine you. A urine test will show if you are losing protein from the kidneys. Blood tests, a chest X-ray and an electrocardiogram (EKG) also may be done.