What condition is characterized by an abnormal presence of large amounts of fluid in body tissues?

The condition characterized by an abnormal presence of large amounts of fluid in body tissues is known as edema. Edema occurs when there is an imbalance between the amount of fluid that leaves the blood vessels and the amount that is returned to them. This can happen due to various reasons such as inflammation, heart problems, kidney disease, or nutritional deficiencies, among others. The excess fluid builds up in the interstitial spaces, leading to swelling in the affected areas.

Understanding the nature of edema is essential, especially in clinical settings, as it can indicate underlying health issues that require attention. For instance, localized edema can occur following an injury, while generalized edema may suggest systemic conditions impacting fluid balance in the body. This condition manifests visually as swelling and can be accompanied by other symptoms depending on the underlying cause.

The other options do not fit the description: fascitis refers to inflammation of the fascia, encephalopathy relates to brain pathology or dysfunction, and fibrillation involves irregular heartbeats rather than fluid accumulation.