Which physical characteristic is one of the first signs of AGN?

Puffiness of the face is indeed one of the earliest physical signs of acute glomerulonephritis (AGN). This condition often leads to fluid retention and edema due to impaired kidney function. The kidneys are responsible for maintaining fluid balance in the body, and when their function is compromised, excess fluid can accumulate in various areas.

Facial puffiness, particularly around the eyes, is especially prominent because of the gravitational effects of fluid pooling in these areas. This characteristic is a common clinical observation and can serve as an initial indicator of kidney-related issues. Recognizing facial puffiness as a symptom is crucial in identifying and managing AGN early in the clinical course to prevent further complications related to compromised kidney function.