Final answer:
Lymphedema is the collection of fluid in tissues, caused by a malfunctioning lymphatic system, leading to swelling and potentially serious medical consequences.
Step-by-step explanation:
The collection of fluid in tissues is known as lymphedema. This occurs when the lymphatic system is unable to properly drain lymph, the fluid that bathes tissues and organs. Lymphedema can result from a damaged or blocked lymphatic system due to cancer cells, injury, or other forms of obstruction. It involves symptoms such as swelling of the subcutaneous tissues, increased limb size, and stretched, tight skin. A distinctive feature of lymphedema is the presence of pitting edema, where a finger pressed against the skin leaves a persistent depression.