Edema

Basics

Description

  • Clinically apparent accumulation of extravascular fluid due to a derangement in the balance of oncotic and hydrostatic forces:
    • Increase in venous/capillary hydrostatic pressure
    • Decrease in plasma oncotic pressure
    • Increase in interstitial oncotic pressure
    • Increase in capillary permeability
    • Increase in lymphatic pressure due to obstruction
    • Combination of these factors
  • Generalized, as with CHF or nephrotic syndrome
  • Localized, as with deep vein thrombosis
  • Increased venous hydrostatic pressure or decreased oncotic pressure results in pitting edema
  • Protein-rich extravasated fluid results in nonpitting edema
  • In certain disorders, there is no clear relation to Starling forces:
    • Idiopathic (cyclic) edema:
      • Worsened with heat
      • More common in women
      • Not necessarily related to menses

Etiology

  • Generalized:
    • Heart failure
    • Cor pulmonale
    • Cardiomyopathies
    • Constrictive pericarditis
    • Pulmonary HTN:
      • Sleep apnea
      • COPD
    • Acute glomerulonephritis
    • Renal failure
    • Medication related (often secondary to salt retention):
      • Steroids/estrogens/progestins
      • NSAIDs
      • Antihypertensives (especially vasodilators)
      • Minoxidil
      • Sympathetic blockers (clonidine, guanethidine, methyldopa)
      • Lithium
      • Insulin
      • Thiazolidinediones (glitazones)
      • Growth hormone
      • Interleukin-2
      • MAOIs
      • Pramipexole
      • Docetaxel
      • Cyclosporine
      • OKT3 monoclonal antibody
      • Acute withdrawal of diuretics
    • Idiopathic (cyclic) edema
    • Myxedema
    • Cirrhosis
    • Nephrotic syndrome
    • Protein-losing enteropathy/malabsorption
    • Starvation
    • Pregnancy
  • Localized:
    • Deep vein thrombosis
    • Venous insufficiency
    • Thrombophlebitis
    • Chronic lymphangitis
    • Cellulitis
    • Baker cyst
    • Vasculitis
    • Angioedema:
      • Allergic
      • Acquired
    • Hypothyroidism (myxedema)
    • Mechanical trauma
    • Thermal injuries
    • Radiation injuries
    • Chemical burns
    • Hemiplegia
    • Reflex sympathetic dystrophy
    • Compressive or invasive tumor
    • Postsurgical resection of lymphatics
    • Post irradiation
    • Filariasis

There's more to see -- the rest of this topic is available only to subscribers.

© 2000–2025 Unbound Medicine, Inc. All rights reserved