Internal causes of edema:
• Liver problems – insufficient protein synthesis and deficient urea synthesis;
• Kidney diseases – damage to the kidney resulting in water retention.
2. External causes of edema:
• Presence of excess fluid in the liver, intestines, heart, lungs, and brain.
• Presence of gases in the intestines;
• Inadequate circulation due to inadequate blood flow.
• Insufficient venous return (blood returning from lower extremities).