Many factors can cause edema, or swelling, in the feet. Swelling to the feet can be a natural occurrence of prolonged sitting or standing or from pregnancy. Trauma, infection and disease processes can also cause swelling to the feet and lower extremities. Because of this fact, people with edema of the feet, especially frequent recurrent or continuous swelling without a known cause, should seek medical care to determine the cause.
Prolonged Standing
Prolonged standing or sitting can cause lower leg and foot edema. In the case of standing, swelling may occur because of the effects of gravity or from less than efficient leg veins, which allow blood to pool in the lower extremities. Sitting, especially with legs crossed, interferes with the return of blood to the heart and swelling results. People traveling for long periods of time, particularly air travel, should change position or stand if possible every hour.
Pregnancy
The gravid uterus puts pressure on the vena cava, the great blood vessel that returns blood to the heart. As pregnancy progresses, particularly during the third trimester, swelling to the feet and ankles can occur.
Venous Insufficiency
Blood is returned to the heart by means of a pressure gradient. The valves in veins prevent blood from draining back down the venous system due to the effects of gravity. With age, the valves in the veins of the lower legs become less competent and mild foot swelling may occur, especially after prolonged sitting or standing. However, for some individuals, the problems are far more serious. Edema to the feet can become chronic and cause decreased circulation to the tissues resulting in skin breakdown and sensory impairment. A doctor should evaluate chronic edema in the feet.
Trauma
Soft tissue injury like a sprained ankle may cause edema in the feet. Joint and tendon injuries like an Achilles tendon rupture and fractures cause edema and require medical care.
Infection
An infection in the tissues of the lower extremities and feet, such as cellulitis, can cause edema. Systemic infections that cause the lymph nodes in the lymphatic system to swell may also cause lower extremity swelling.
Heart Failure
When the heart does not pump properly, fluid tends to build up in the peripheral vascular system. A symptom of heart failure is edema in the feet. However, other symptoms such as shortness of breath, cough and fatigue usually accompany the swelling.
Liver Cirrhosis
End-stage liver disease will cause swelling to the feet and lower extremities. As the liver swells, it compresses the vena cava and impedes blood return to the heart. Other symptoms would precede foot swelling.
Kidney Failure
When the kidneys cannot remove fluid from the body as in kidney failure, swelling to the feet occurs. As the disease progresses, so too does the swelling, and many other symptoms arise. A doctor should evaluate edema to the feet, which recurs or is prolonged, as this symptom could be an indicator of kidney function problems.
References
- "Medical-Surgical Nursing-Patient Centered Collaborative Care"; Donna D. Ignatavicius & M. Linda Workman; 2010
- American Heart Association: "Signs and Symptoms of CHF"
- The Mayo Clinic: Leg Swelling
