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Some Causes of Edema

Some Causes of Edema


Suggestive Findings

Diagnostic Approach*

Increased hydrostatic pressure, fluid overload

Right heart failure (primary or secondary to left-sided disease or to constrictive pericarditis) directly increasing venous pressure

Symmetric, dependent, painless, pitting edema, often with dyspnea during exertion, orthopnea, and paroxysmal nocturnal dyspnea

Commonly, lung crackles, S3 or S4 gallop or both, jugular venous distention, hepatojugular reflux, and Kussmaul sign

Chest x-ray and ECG

Pregnancy and premenstrual state

Symmetric, dependent, painless, usually mild pitting edema

Apparent by history

Clinical evaluation

Drugs (eg, minoxidil, NSAIDs, estrogens, fludrocortisone, dihydropyridine, diltiazem, other calcium channel blockers)

Symmetric, dependent, painless, usually mild pitting edema

Clinical evaluation

Iatrogenic (eg, excessive intravenous fluids)

Symmetric, dependent, painless, usually mild pitting edema

Apparent by history and medical record

Clinical evaluation

Increased hydrostatic pressure, venous obstruction


Acute, pitting edema in a single, usually lower extremity, usually with pain; sometimes Homans sign (pain in the calf when the foot is dorsiflexed)

Redness, warmth, and tenderness; possibly less marked than in soft-tissue infection

Sometimes a predisposing factor (eg, recent surgery, trauma, immobilization, hormone replacement, cancer)


D-dimer testing

Chronic edema in one or both lower extremities, with brownish discoloration, discomfort but not marked pain, and sometimes skin ulcers

Often associated with varicose veins

Clinical evaluation

Extrinsic venous compression (by tumor, a gravid uterus, or marked abdominal obesity)

Nonpainful, slowly developing edema

If tumor compresses the superior vena cava, usually facial plethora, distended neck veins, and absent venous pulse waves above the obstruction

Clinical evaluation

Ultrasonography or CT if tumor is suspected

Prolonged absence of skeletal muscle pumping activity on extremity veins

Prolonged immobility (eg, being bedbound or on a long airline flight)

Painless, symmetric, dependent edema

Clinical evaluation

Decreased plasma oncotic pressure†

Diffuse edema, often significant ascites, and sometimes periorbital edema

24-hour urine collection to check for protein loss

Serum albumin level

Protein-losing enteropathy

Significant diarrhea

Testing for cause

Sometimes endoscopy

Sometimes serum and 24-hour stool testing for alpha-1-antitrypsin

Reduced albumin synthesis (eg, in liver disorders or undernutrition)

Often with significant ascites

Causes often apparent by history

If cause is a chronic liver disorder, often jaundice, spider angiomas, gynecomastia, palmar erythema, and testicular atrophy

Serum albumin, liver function tests, PT/PTT

Increased capillary permeability

Angioedema (allergic, idiopathic, hereditary)

Sudden, focal, asymmetric, nondependent, pink or skin-colored edema that is sometimes uncomfortable

Clinical evaluation

Injury (eg, burns, chemicals, toxins, blunt trauma)

Focal edema, sometimes erythematous; causes apparent by history

Clinical evaluation

Severe sepsis (causing vascular endothelial leakage)

Obvious sepsis syndrome with fever, tachycardia, focal infection

Painless, symmetrical edema


Imaging studies as needed

Soft-tissue infection (eg, cellulitis, necrotizing myofasciitis)

If due to cellulitis, usually redder and more painful and tender than that due to angioedema and more circumscribed than that due to DVT

With necrotizing infections, severe pain, constitutional symptoms

Clinical evaluation


Sometimes ultrasonography to rule out DVT

Lymphatic obstruction

Iatrogenic (eg, after lymph node dissection in cancer surgery or after radiation therapy)

Etiology usually apparent by history

Initially pitting edema, with fibrosis developing later

Clinical evaluation

Congenital (rare)

Often onset in childhood, but for some types, only later onset

May be familial

Sometimes lymphoscintigraphy

History of being in an endemic area in a developing country

Usually focal edema, sometimes involving the genitals

Microscopic examination of blood smear

* Most patients with generalized edema require complete blood count (CBC), electrolytes, blood urea nitrogen (BUN), creatinine, liver function tests, serum protein measurement, and urinalysis (to check for proteinuria).

† Decreased plasma oncotic pressure often triggers secondary sodium and water retention, leading to fluid overload.

DVT = deep venous thrombosis; NSAIDs = nonsteroidal anti-inflammatory drugs; S3 = 3rd heart sound; S4 = 4th heart sound.