Which of the following is a common sign or symptom of uremia?

Uremia is a clinical syndrome that occurs when the kidneys are unable to filter waste products from the blood effectively, leading to an accumulation of toxins. Edema is a common symptom associated with uremia, primarily due to fluid overload resulting from compromised kidney function. When the kidneys are not functioning properly, they can't effectively regulate fluid balance, leading to swelling in various parts of the body, particularly the lower extremities. This swelling is due to the retention of sodium and water, characteristic of renal failure.

High blood pressure is also a potential issue in uremia, but it is more of a systemic effect rather than a direct symptom of uremia itself. Excessive thirst can be seen in various conditions, including diabetes mellitus and diabetes insipidus, but it is not specific to uremia. Similarly, visual disturbances might occur from other causes related to renal failure, such as electrolyte imbalances or hypertension but are not defining features of uremia. Hence, edema stands out as a direct manifestation of the fluid retention and regulation issues associated with uremic syndrome.