If you have swelling in one leg, along with pain, low-grade fever, and possibly a change in color of the affected leg, call your doctor immediately. Treatment with blood thinners may be necessary. Heart, liver, or kidney disease. Sometimes swelling can indicate a problem such as heart, liver, or kidney disease.Why do my legs look swollen?
Leg swelling isn't always a sign of a heart or circulation problem. You may often experience swelling due to fluid buildup from being overweight, being inactive, after sitting or standing for a long time, or wearing tight stockings. Factors related to fluid buildup include: Acute kidney failure.