A vascular system dysfunction, which causes swelling and adds weight to the legs, is the usual cause of leg heaviness, states Foot Smart. Lymphedema, poor circulation in the legs and chronic venous insufficiency are common dysfunctions. Leg heaviness during walking is not normal and may have an underlying condition.
Lymphedema leads to accumulation of excess lymphatic fluid in the subcutaneous tissues. Swelling, or edema, occurs because lymph vessels that return fluids back to the heart are blocked, impaired or destroyed, resulting in accumulation of fluid in the extremities.
In chronic venous insufficiency, a condition that can be caused by thrombophlebitis or deep vein thrombosis, blood clots can occur in the veins, obstructing the normal flow of blood and causing pooling of blood in the lower legs. In venous insufficiency, heaviness of the legs is associated with pain and soreness. The hallmark of the condition is pain after movement.
According to Medscape, people suffering from chronic venous insufficiency should wear compression stockings, avoid prolonged standing or sitting, and regularly walk or perform calf-muscle exercises. To help relieve edema, Foot Smart recommends elevation of the legs periodically during the day and while sleeping, walking programs to increase blood flow and use of pneumatic compression devices.