What can cause edema in tissues?

Edema in tissues is often caused by increased filtration, which refers to the movement of fluid from the bloodstream into the interstitial spaces of tissues. This process can occur when the hydrostatic pressure within capillaries rises, pushing more fluid out than normal. Factors that contribute to increased filtration include higher blood pressure, increased capillary permeability, or conditions that alter the balance between hydrostatic and osmotic pressures.

When the filtration rate exceeds the reabsorption rate of fluids back into the capillaries, it leads to an accumulation of fluid in the tissues, resulting in edema. Understanding this mechanism is crucial for grasping how various physiological conditions can lead to swelling and fluid imbalances in the body.