The pressure overload of venous insufficiency exacts its toll by causing (1) edema, (2) discoloration, (3) pain, and (4) injury to the tissue. The symptoms produced in this disorder have certain typical features, yet there is also a wide variability among individuals.
The combination of unrelieved hydrostatic pressure and the high pressure from the muscular force of walking operate in concert to jeopardize the tissue of the lower legs. Leakage of protein-containing serum and red blood cells from the capillaries occurs as a result of chronic venous hypertension. While varicose veins alone can cause these symptoms, they are most prominent in people with reflux in the deep and perforating venous systems.
Venous insufficiency of the deep system in the legs causes swelling in a characteristic pattern. It occurs as the result of persistent, excessive pressure which favors movement of fluid from the blood into the space between cells of the fixed tissue. The lower legs are the principle site of edema formation because here the hydrostatic pressure on standing and sitting is greatest.
Swelling typically begins with a slight puffiness just above the inner ankle bone where the skin is somewhat looser than that of nearby areas. With prolonged standing, swelling extends upward somewhat and across the front of the ankle. A temporary depression (or pit) is left momentarily after the swollen skin is compressed firmly with a fingertip; the applied pressure forces fluid away from the point of contact. Return to the original contour after release takes a minute or two. The depression has led to the name “pitting edema.”
In the early years after acquiring venous insufficiency, a person notices ankle swelling only near the end of the day after prolonged upright activity. During a night’s sleep, hydrostatic pressure is drastically reduced for many hours. Edema fluid is gradually reabsorbed from the tissue spaces into the capillaries and veins and the central circulation. By morning, the ankles are at first completely free of edema. For many with mild swelling, even a short period of leg elevation during the day will reduce the edema appreciably. Eventually, the person finds that swelling is still present on rising in the morning, although to a lesser degree than on retiring at night.
Leg swelling in venous insufficiency is exaggerated in many commonplace situations:
during prolonged standing (increased hydrostatic pressure);
in a hot climate (exaggerated vascular dilation);
after consumption of large amounts of salt (water retention from excessive sodium); and
just before menstruation (water retention from hormonal changes).
A difference in size of the lower legs may be the earliest evidence of venous insufficiency. Even a slight discrepancy can be detected on careful inspection. In this example, the left calf ...