Edema

From Greek: οιδημα (eudima) - swelling Synonym: Dropsy, hydrops German:' Ödem, "Wasseransammlung" (umgangsspr.)

1 Definition

The term Edema is designated for the build-up of fluids in the vascular system and their accumulation in interstitial space. Clinically, the term “edema� primarily stands for the accumulation of fluids in the subcutis (anasarca) and in certain organs (for instance, lung edema and brain edema).

2 Classification

2.1 According to pathogenesis

• Protein-poor edema (transudate)
  • Colloid osmotic edema: Missing reabsorption of tissue fluids in the venous thigh of the vascular system through the degradation of oncotic vascular pressure
  • Hydrostatic edema: Enhanced filtration of fluids from the vascular system into the surrounding tissues by the rise of the hydrostatic vascular pressure or the increase in blood volume
  • Mechanical edema: Drainage obstruction of the filtered tissue fluid by the lymph system
• Protein-rich edema (exudate)
  • Inflammatory edema: Increase of the vascular permeability by inflammation-induced mediator substances.

3 According to localization

• Generalized edema *Regional edema

4 Causes

The potential causes for edema are varied. Among others are: ===Causes for generalized edema===

• Cardiac causes
  • Right heart failure
  • Global insufficiency
• Renal causes
  • Renal failure
  • Nephrotic syndrome
  • Acute glomerulonephritis
• Gastrointestinal causes
  • Liver failure
  • Maldigestion syndrome
  • Malabsorption syndrome
• Endocrine causes
  • Hyperaldosteronism
  • Myxedema
• Medicines
  • Antihypertensives (e.g. calcium antagonists)
  • Anti-inflammatory drugs
  • Laxatives
  • Glucocorticoids
  • Diuretics
  • Antidepressants
• Alimentary causes
  • Hunger
  • Kwashiorkor
  • Pregnancy
  • Idiopathic

4.1 Causes for regional edema

• Static strain (sitting, standing, etc.)
• Lymph drainage disturbances
  • Tumores
  • Filariasis
  • Irradiation
• Venous drainage disturbance
  • Chronic venous insufficiency
  • Phlebothrombosis
• Allergies
  • Quincke’s edema
  • Angioedema
• Hereditary angioedema
• Infections
• Traumas

5 Clinical description

The symptoms caused by edema depend on the affected part of the body and/or organ. Edema of the extremities is primarily noticeable as painless swelllings, which leads to a circumferential augmentation of the affected area and, as the case may be, a feeling of pressure. Mainly visible or palpable edema of the lower extremities is detected by a simple body examination. They are, among others:

• Pretibial edema
• Ankle edema

6 Special forms of edema

• Brain edema or cerebral edema
• Hunger edema
• Lid edema
• Lung edema
• Lymphedema
• Macular edema
• Quincke’s edema
• Pregnancy edema