What can trigger positive interstitial fluid pressure?

Positive interstitial fluid pressure can occur when there is leakage from blood vessels, as this leads to an accumulation of fluid in the interstitial space. When blood vessels become permeable due to various reasons such as injury or inflammation, proteins and fluid can escape from the vascular system into the surrounding tissue. This increased fluid in the interstitial space raises the interstitial fluid pressure, which can impact tissue perfusion and contribute to conditions like edema. In essence, the leakage creates an imbalance that elevates fluid levels outside of the vascular system, directly resulting in positive interstitial fluid pressure.