Final answer:
Decreased kidney function can lead to hypervolemia, increasing the risk of hypertension and congestive heart failure, and possibly causing azotemia and uremia. Edema as a result of fluid retention also indicates underlying conditions such as chronic liver disease, and treating it requires correcting the primary cause.
Step-by-step explanation:
Decreased kidney function and the consequent fluid retention can lead to a condition known as hypervolemia, which results in several medical complications. Hypervolemia increases the risk of developing hypertension and congestive heart failure, as the body struggles to cope with the excess fluid. Furthermore, the retention of toxins such as urea can lead to azotemia, and if left untreated, further progress into uremia, which encompasses a range of symptoms from lethargy to more severe conditions like pericarditis and encephalopathy.
Additionally, the accumulation of fluid, or edema, is often a sign of an underlying medical issue such as severe protein deficiency, renal failure, liver cirrhosis, or injury to blood and lymphatic vessels. Treatment of edema therefore requires addressing its root cause to restore the body's fluid balance and alleviate symptoms. For instance, chronic liver disease can decrease the production of plasma proteins, thereby reducing colloid osmotic pressure in the capillaries and allowing water to leak into surrounding tissues, causing edema.