This document discusses transudate and exudate, types of edema fluid. Transudate results from increased hydrostatic pressure or decreased plasma proteins, causing protein-poor fluid to accumulate. Exudate occurs due to increased vascular permeability in inflammatory conditions, producing protein-rich fluid. The main differences between transudate and exudate are that transudate is clear and serous with low protein, cells and LDH, while exudate is cloudy/purulent with high protein, cells including neutrophils, and LDH. Transudate results from non-inflammatory causes while exudate occurs due to inflammation.

1. ● Edema
● Transudate vs Exudate
Dr. Salman Ansari
Dept. of Pathology
Kanachur Institute of Medical Sciences

2. ● Normal physiology
● Edema - types and causes
● Transudate
● Exudate
● Differences between transudate and exudate
Contents

3. Physiology
Exudation: process of escape of fluid from blood vessels
into extravascular space
Edema: defined as accumulation of excess of fluid in
interstitial tissues

4. Forces acting on the blood vessel normally:
1) Hydrostatic pressure: force exerted by blood within the blood
vessel(pushes fluid out)
1) Colloid osmotic pressure: force exerted by plasma proteins
to keep fluid within the blood vessel(pulls the fluid in)
1) Membrane is not very permeable, so it does not allow much
fluid or cells to leak outside

5. HP COP
≈
Fluid remains inside the vessel
NORMAL

6. HP COP
≠
EDEMA
ABNORMAL

7. Edema
Local edema
Generalised edema

8. Causes
Local edema Generalised edema
- Inflammation
- Urticaria(hives)
- Obstruction in vein(DVT)
- Lymphatic obstruction: Post
surgery/post irradiation,
filariasis
- Neoplastic
1) Increased HP:
- Congestive heart failure
- Venous obstruction
1) Decreased
COP(hypoproteinemia):
- Nephrotic syndrome
- Liver cirrhosis(ascites)
- malnutrition

9. Types
Transudate
Exudate

10. Transudate
Edema caused due to increased hydrostatic pressure or
decreased plasma proteins is called transudate
- It is protein-poor
- Seen in heart failure, renal failure and hepatic failure

11. Transudate
- Non-inflammatory causes
- Clear serous fluid, with straw yellow
- low specific gravity
- Does not clot
- Few cells present
- Bacteria: absent
- LDH: low

12. Exudate
Edema fluid due to increased vascular permeability in
inflammatory conditions is called exudate
- Protein-rich
- Due to inflammatory causes

13. Exudate
- cloudy/purulent/hemorrhagic
- Yellow to red
- High specific gravity
- Clots spontaneously(due to high fibrinogen)
- High cell count - neutrophils
- Bacteria: present
- LDH is high

15. Characteristic Transudate Exudate
Mechanism Due to non-inflammatory process(high HP) &
normal vascular permeability
Inflammatory process with increased
vascular permeability
Appearance Clear, serous fluid Cloudy/purulent/hemorrhagic
Colour Straw yellow Yellow to red
Specific gravity <1.018 >1.018
Protein Low(<2 g/dl) High(>2 g/dl)
Clot Absent Present
Cell count Low High
Type of cell Few lymphocytes Neutrophils, lymphocytes
Bacteria Absent Usually present
LDH Low High

16. For notes,
scan:
References:
● Ramadas Nayak - Textbook of Pathology for Allied
Health Sciences
Questions:
salman.s.ansari92@gmail.com
For PPT, scan: