Swelling from a fluid imbalance in the cells or from a response to injury, infection, or medication is called:

Swelling due to a fluid imbalance in the cells or as a response to injury, infection, or medication is termed edema. Edema occurs when excess fluid accumulates in the tissues, which can be a result of various factors, including inflammation, which leads to changes in vascular permeability and increased blood flow to the affected area. This fluid buildup causes the characteristic swelling, often seen in conditions like allergic reactions, injuries, or certain medical conditions affecting the heart or kidneys.

The term infiltration generally refers to the process by which substances penetrate or permeate tissues, which does not specifically imply fluid imbalance or swelling. Inflammation is the body's general response to injury or infection and involves a complex cascade of biological responses, but while it can lead to edema, it is a broader term that encompasses many physiological changes. Excoriation describes a skin condition involving abrasions or scratches, which does not relate to swelling or fluid retention. Thus, edema is the most precise and accurate term for the described swelling due to fluid imbalance or tissue response.