You are here: Home » Pathology » Edema


This movie requires Flash Player 9

Outline of Lecture


Movement Of Fluid Across Capillaries

Capillary (hydrostatic) pressure

Interstitial fluid (hydrostatic) pressure

Plasma oncotic pressure

Interstitial fluid oncotic pressure




An increased volume of interstitial fluid (ISF) in a tissue or organ.

May be localised or generalised (systemic)

Causes of Oedema

Raised capillary pressure

Reduced oncotic pressure

Increased capillary permeability

(Endothelial damage)

Impaired lymphatic drainage

I- Increased Venous Pressure
Raised Capillary Pressure

Cardiac failure

right ventricular failure – systemic oedema

left ventricular failure – pulmonary oedema

congestive cardiac failure – both


Local venous obstruction

deep vein thrombosis

external compression

SVC obstruction




Right Ventricular Failure

Raised jugular venous pressure also seen

Enlarged liver also common due to congestion (nutmeg liver)

Pulmonary Oedema

Usually caused by LVF

Raised pressure across pulmonary capillaries

Causes shortness of breath

Due to ischemic heart disease or hypertension

Pulmonary Oedema

Congestive Heart Failure

Combination of left and right ventricular failure

Common in ischemic heart disease

Causes systemic and pulmonary oedema

Pregnancy Oedema

Commonly occurs in the lower limbs due to pressure on Pelvic nerve

II- Reduced Oncotic Pressure
(Decreased Plasma Proteins)

Renal disease

loss of albumin across glomerulus

Hepatic disease

inadequate albumin synthesis


inadequate albumin intake in dite

III- Increased Capillary Permeability

Allergia (histamine increases capillary permeability).

Insects bite.

Severe hot.

Frost bite: (severe cold)

Bacterial toxins

IV- Lymphatic Obstruction


Elephantiasis (Filariasis)



Congenital abnormality

Generalised Oedema

Congestive cardiac failure

Right ventricular failure

Renal disease

Liver disease

Cerebral Oedema

Causes: increased intracranial pressure

Fatal if left untreated

Generalised in hypoxia, injury

Surrounding other lesions eg tumour, abscess

Fluid in Body Cavities

Pleural effusion

heart failure, inflammation, tumour

Pericardial effusion

inflammation, tumour

Ascites (peritoneal effusion)

cirrhosis, heart failure, tumour

Pleural Effusion

Pericardial Effusion



Most severe cases associated with

cirrhosis of the liver

intra-abdominal malignancy

Browse all Presentations on Pathology

Leave a Reply

Your email address will not be published. Required fields are marked *


Scroll To Top