This document discusses edema, which is an abnormal accumulation of fluid in the interstitial spaces of tissues. It describes how water normally moves between blood vessels and tissues and is drained by lymphatic vessels. Edema occurs when fluid movement into tissues exceeds drainage. The main causes of edema include increased hydrostatic pressure, reduced plasma colloid osmotic pressure, lymphatic obstruction, sodium retention, and inflammation. Edema can occur in subcutaneous tissues, lungs, brain, and other body areas and cavities. The clinical consequences range from minor to life-threatening depending on the location and severity of the edema.

1. EDEMA
By ; HARITH RIYADH

2. interdaction
• Approximately 60% of lean body weight is water. Two
thirds of the body's water is intracellular, and the
remainder is in extracellular compartments, mostly
the interstitium (or third space) that lies between
cells; only about 5% of total body water is in blood
plasma. The movement of water and low molecular
weight solutes such as salts between the
intravascular and interstitial spaces is controlled
primarily by the opposing effect of vascular
hydrostatic pressure and plasma colloid osmotic
pressure

3. • Normally the outflow of fluid from the arteriolar end of the
microcirculation into the interstitium is nearly balanced by inflow at the
venular end; a small residual amount of fluid may be left in the
interstitium and is drained by the lymphatic vessels, ultimately returning
to the bloodstream via the thoracic duct. Either increased capillary
pressure or diminished colloid osmotic pressure can result in increased
interstitial fluid If the movement of water into tissues (or body cavities)
exceeds lymphatic drainage, fluid accumulates. An abnormal increase in
interstitial fluid within tissues is called edema, while fluid collections in
the different body cavities are variously designated hydrothorax,
hydropericardium, and hydroperitoneum (the last is more commonly
called ascites).

4. • Anasarca is a severe
and generalized
edema with
widespread
subcutaneous tissue
swelling.

5. Pathophysiologic Categories of Edema
•INCREASED HYDROSTATIC
PRESSURE
• Impaired venous return
• Congestive heart failure
• Constrictive pericarditis
• Ascites (liver cirrhosis)
• Venous obstruction or compression
• Thrombosis
• External pressure (e.g., mass)
• Lower extremity inactivity with prolonged dependency
• Arteriolar dilation
• Heat
• Neurohumoral dysregulation

6. REDUCED PLASMA OSMOTIC
PRESSURE (HYPOPROTEINEMIA)
• Protein-losing glomerulopathies (nephrotic
syndrome)
• Liver cirrhosis (ascites)
• Malnutrition
• Protein-losing gastroenteropathy

7. LYMPHATIC OBSTRUCTION
• Inflammatory
• Neoplastic
• Postsurgical
• Postirradiation

8. SODIUM RETENTION
• Excessive salt intake with renal insufficiency
• Increased tubular reabsorption of sodium
Renal hypoperfusion
• Increased renin-angiotensin-aldosterone
secretion

9. INFLAMMATION
• Acute inflammation
• Chronic inflammation
• Angiogenesis

10. • Subcutaneous edema
can be diffuse or more
conspicuous in regions
with high hydrostatic
pressures.
• In most cases the
distribution is influenced
by gravity and is termed
dependent edema (e.g.,
the legs when standing,
the sacrum when
recumbent).
• .

11. • Edema as a result of
renal dysfunction can
affect all parts of the
body. It often initially
manifests in tissues
with loose connective
tissue matrix, such as
the eyelids; periorbital
edema is thus a
characteristic finding in
severe renal disease

12. • With pulmonary
edema, the lungs are
often two to three
times their normal
weight, and sectioning
yields frothy, blood-
tinged fluid—a mixture
of air, edema, and
extravasated red cells.

13. • Brain edema can be
localized or generalized
depending on the nature
and extent of the
pathologic process or
injury. With generalized
edema the brain is
grossly swollen with
narrowed sulci;
distended gyri show
evidence of compression
against the unyielding
skul

14. pitting edema
• it’s way for diagnosis
edema
• Finger pressure over
substantially
edematous
subcutaneous tissue
displaces the
interstitial fluid and
leaves a depression, a
sign called pitting
edema

15. Clinical Consequences.
• The consequences of edema range from merely
annoying to rapidly fatal. Subcutaneous tissue
edema is important primarily because it signals
potential underlying cardiac or renal disease;
however, when significant, it can also impair
wound healing or the clearance of infection.
Pulmonary edema is a common clinical problem that is
most frequently seen in the setting of left ventricular
failure; it can also occur with renal failure, acute
respiratory distress syndrome , and pulmonary
inflammation or infection

16. • . Not only does fluid collect in the alveolar septa around
capillaries and impede oxygen diffusion, but edema fluid
in the alveolar spaces also creates a favorable
environment for bacterial infection. Brain edema is life-
threatening; if severe, brain substance can herniate
(extrude) through the foramen magnum, or the brain stem
vascular supply can be compressed. Either condition can
injure the medullary centers and cause death