Swelling of the legs is abnormal and should be evaluated by a medical professional if it occurs on a regular basis. Leg swelling is common in individuals with venous insufficiency especially after a long day of sitting or standing. Heaviness is common with chronic swelling, however pain or tenderness in the legs associated with swelling is an especially important reason to seek evaluation. While some of the causes of leg swelling may be minor or expected like in the case of a sprained ankle. Swelling after travel, surgery require very urgent medical care to reduce the likelihood of major complications or death. Untreated leg swelling may be a symptoms related to other complications such as infection, poorly-healing wounds, or blood clots in leg.
Evaluation of leg swelling begins with a review personal and family medical history, symptoms and risk factors. The most common failure of diagnosis occurs due to a venous ultrasound study which is performed in a manner to rule out DVT and does not include the analysis of the veins from incompetence or reflux. It is very common for a referring doctor to be told that the ultrasound is “normal” or “was negative for DVT” while failing to test for venous insufficiency.
Leg swelling can be bilateral or it may be unilateral. The causes of swelling in one leg may be similar to the other leg, but it is not unusual for different factors to cause the swelling in each leg. Leg swelling can be caused by more than one factor such as venous insufficiency, obesity, increased right sided heart pressures and previous saphenous vein harvest for heart bypass surgery.
Swelling may occur due to high pressure in the veins of the legs, local injury, inflammatory changes, obstruction of lymphatic fluid outflow, infection, low blood protein levels, obesity, pregnancy, fluid retention states, or drug effects. High pressure in the veins of the legs results in fluid, proteins, and blood cells leaking through the wall of small veins into the soft tissues, especially near the ankles. This causes pitting edema, swelling which will leave a temporary indentation in the skin with pressure from a shoe, sock, or intentional pressure such as a squeeze with a finger.
Chronic leg swelling may also be due to states that result in generalized body fluid expansion which may be more apparent in the legs due to the effect of gravity such as:
Congestive or ischemic heart failure, pulmonary hypertension, pericarditis which limits heart pumping function, pregnancy, Idiopathic edema, often involving both upper and lower extremities in premenopausal women, liver disorders, kidney disorders, hypothyroidism, low protein states such as malnutrition, protein loss due to illness, kidney, or intestinal diseases.
Cellulitis, infection of the skin and fatty tissues of the leg may cause swelling with pain and tenderness. Pain from cellulitis may be very severe or may manifest as tenderness and mild pain with faintly pink to bright red skin.
Swelling of the foot, especially if the skin does not pit with brief application of pressure, may be due to lymphedema, a failure of the microscopic network of channels which move tissue fluid from the extremity back to the blood stream at the level of the upper chest. Some of the causes of lymphedema include:
Congenital—present at birth,
Acquired– due to recurrent infection or obstruction
Post-surgical—excision of vein for vein grafts, lymph node dissection for tumor,
Malignancy—lymphoma or other diseases affecting the lymph nodes,
Obesity—due to compression of lymphatic channels in the abdomen or pelvis.
After venous insufficiency, obesity is the next most common cause of lower extremity swelling in the United States. Abdominal obesity partially obstructs venous outflow and lymphatic outflow from the legs. Obesity also accelerates the stretching of the leg veins due to the effects of gravity, thus contributing to the progression of venous insufficiency.
Treatment of lower extremity swelling depends upon the cause. Frequently, conservative measures are helpful and these often are started before the cause of the swelling is fully evaluated. Conservative measures may include:
Weight loss, if applicable, periodic elevation of the legs higher than the heart, avoiding prolonged sitting or standing, performing calf muscle pump exercises frequently when sitting or standing,
routine daily use of graduated compression support hose, often rated at a compression level of 20-30 or 30-40 mm Hg.