Learning Objective: By the end of this section, the learner should be able to describe the mechanisms, types, and clinical significance of edema, distinguish pitting from non-pitting edema, and relate each type to underlying Starling forces and lymphatic function.
Edema (Pathology Integration)
Edema is the accumulation of excess fluid in the interstitial space and can present in two major forms:
Pitting Edema (most common)
- Pressing the swollen area leaves a persistent indentation.
- Caused by excess interstitial fluid with normal protein concentration.
- Diuretics are effective because they remove fluid and reduce swelling.
Non-Pitting Edema
- Pressing the area does not leave an indentation.
- Caused by high interstitial protein levels, increasing oncotic pressure (e.g., lymphedema, myxedema).
- Diuretics are usually ineffective, as the issue is protein accumulation rather than free fluid.
