Summary
Peripheral edema is the presence of excess interstitial fluid in the tissue of the extremities, which causes palpable swelling.[1]
Edema develops when microvascular filtration, and therefore interstitial fluid production, exceeds lymph drainage for a sustained period. This could be because the microvascular filtration rate is high, lymph flow is low, or both.[2]
[Figure caption and citation for the preceding image starts]: Development of edema: an imbalance between the filtration of fluid from the bloodstream and drainage via the lymph system.Created by BMJ Knowledge Centre [Citation ends].
The body has a number of homeostatic mechanisms that serve to maintain interstitial fluid balance, and these must be overwhelmed before fluid buildup becomes evident as peripheral edema. Clues generated by the history, physical examination, and targeted evaluation help to identify the factors affecting lymphatic drainage and microvascular filtration. In many patients, multiple factors contribute to the development of peripheral edema.
Lymphedema is predominantly caused by inadequate lymphatic drainage.
Differentials
Common
- Heart failure with reduced ejection fraction (HFrEF)
- Heart failure with preserved ejection fraction (HFpEF)
- Cor pulmonale
- Sleep apnea
- Deep vein thrombosis
- Chronic venous insufficiency
- Nephrotic syndrome
- Cirrhosis
- Pregnancy
- Medication-induced edema
- Premenstrual edema
Uncommon
- Pericardial effusion
- Constrictive pericarditis
- Restrictive cardiomyopathy
- Tricuspid regurgitation
- Nonthrombotic venous outflow obstruction
- Hepatic venous outflow obstruction (includes Budd-Chiari syndrome and hepatic veno-occlusive disease)
- Renal failure
- Protein-losing enteropathy
- Angioedema
- Sepsis
- Compartment syndrome
- Primary lymphedema
- Secondary lymphedema
- Idiopathic
- Severe malnutrition
- Hypothyroidism/myxedema
- Ruptured popliteal fossa cyst
- Pelvic tumor causing external pressure on pelvic veins
Contributors
Authors
Juan N. Lessing, MD, FACP
Associate Professor, University of Colorado School of Medicine
Department of Medicine
University of Colorado Anschutz Medical Campus
Denver
CO
Disclosures
JNL receives an honorarium to serve as an associate editor of Clinical Excellence Board for Aquifer, Inc., a medical education nonprofit. This role has no specific, tangible, or perceived interest to the BMJ topic, and is not considered a competing interest.
Laura D. Rosenthal, DNP, ACNP, FAANP
Associate Professor, College of Nursing
University of Colorado Anschutz Medical Campus
Denver
CO
Disclosures
LDR declares that she has no competing interests.
Ethan Cumbler, MD
Professor of Medicine
Division of Hospital Medicine
Department of Internal Medicine
University of Colorado
Denver
CO
Disclosures
EC declares that he has no competing interests.
Peer reviewers
Teresa L. Carman, MD, MSVM
Director
Vascular Medicine
University Hospitals Harrington
Heart and Vascular Institute
Cleveland Medical Center
OH
Disclosures
TLC declares that she has no competing interests.
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