Swelling that affects both lower legs and feet usually indicates a systemic condition rather than a localized problem, such as an injury or skin infection. Swollen lower legs and feet signal leakage of fluid from your circulation into the soft tissues, a condition known as peripheral edema. This type of swelling can occur due to something as simple as standing for a long time or might signal a problem with your heart, kidneys or liver.
A small amount of temporary swelling in your lower legs and feet might occur due to a harmless cause, such as standing or sitting for a long period, premenstrual water retention or overindulging in salty foods. Edema of the lower legs and feet also commonly occurs in late pregnancy due to hormone-related water retention and pressure exerted on the venous system by the growing uterus. Water retention with peripheral edema can also occur as a side effect of certain medications, including:
- Birth control pills
- Hormone replacement therapy
- Corticosteroids, such as cortisone and prednisone
- Nonsteroidal anti-inflammatory drugs, such as ibuprofen (Advil, Motrin) and celecoxib (Celebrex)
- Calcium-channel blockers, such as amlodipine (Norvasc), felodipine (Plendil) and nifedipine (Procardia)
Conditions that reduce the heart's pumping ability often lead to pooling of blood in the lower legs and feet due to the effects of gravity. As a result of increased pressure caused by this pooling, fluid leaks into the soft tissues of the lower legs and feet. Congestive heart failure is a leading heart condition associated with peripheral edema, typically accompanied by shortness of breath with physical exertion. Inflammation of the sac surrounding the heart, or pericarditis, can also cause swelling of the lower legs and feet. Heart muscle conditions called cardiomyopathies can provoke this symptom as well.
Your kidneys maintain salt and water balance in your body. Diseases that damage the kidneys and/or disrupt kidney function often lead to abnormal salt and water retention with associated edema. The swelling might involve the face and hands as well as the lower legs and feet. Many kidney diseases can lead to edema. Some develop relatively quickly whereas others evolve slowly over many years, such as diabetic kidney disease.
Liver diseases that severely reduce normal function lead to an array of changes in the body that can result in edema of the lower legs and feet. Fluid might also accumulate in the abdomen, a condition called ascites. Factors that contribute to edema with severe liver disease include reduced production of proteins and increased pressure in the veins that drain into the liver, or portal hypertension. Cirrhosis of the liver, in which the organ becomes severely scarred over several years, is a leading cause of liver-related edema. In the US, alcoholic hepatitis, chronic viral hepatitis and nonalcoholic fatty liver disease are the most common causes of cirrhosis.
Protein malnutrition describes a state in which the amount of protein taken in through your digestive system fails to meet your body's needs. This might occur due to insuffient protein in your diet, impaired digestion and/or absorption of dietary protein, or exceptionally high protein demands caused by a serious illness or injury. With protein malnutrition, the body cannot produce the amount of protein needed, which triggers a fall in the blood protein level. If the blood protein level is markedly reduced, peripheral edema can occur. Examples of conditions and diseases the might lead to protein malnutrition include:
- Anorexia or bulimia
- Inflammatory bowel disease
- Celiac disease
- Gastric bypass surgery
- Acute pancreatitis and pancreatic cancer
The conditions discussed represent the likely causes of swollen lower legs and feet. However, a number of other conditions might be to blame, including:
- Damaged valves in the leg veins, or venous insufficiency
- Abnormal or damaged lymph vessels in the legs or pelvis
- Blood clot in a deep vein of the abdomen or pelvis
- Abdominal or pelvic tumor
- Obstructive sleep apnea
- Underactive thyroid gland, or hypothyroidism
Next Steps, Warnings and Precautions
See your doctor if you notice swelling of your lower legs and feet that seems unrelated to your menstrual cycle for women, prolonged standing or sitting, or eating a lot of salt -- especially if the edema persists for more than a day or two. If you are pregnant, call your obstetrical care provider if you notice a sudden increase in swelling of your feet, lower legs and/or hands.
Seek immediate medical care if you experience rapidly worsening peripheral edema, especially if you have heart or lung disease, or experience any warning signs or symptoms, including:
- Shortness of breath or difficulty breathing
- Chest pain or pressure
- Moderate to severe abdominal bloating
- Dizziness, lightheadedness or fainting
- Fever and/or chills
- Merck Manual Professional Version: Lower-Extremity Edema During Late Pregnancy
- Taylor's Differential Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter, 3rd Edition; Paul M. Paulman, et al.
- General Internal Medicine Consult, 2nd Edition; Geoffrey S. Cislo, et al.
- American Family Physician: Cirrhosis: Diagnosis, Management, and Prevention
- Manual of Family Practice, 2nd Edition; Robert B. Taylor
- American Family Physician: Edema: Diagnosis and Management
- Journal of the American Board of Family Medicine: Approach to Leg Edema of Unclear Etiology