There are many controversial topics relating to renal disease in hospitalized patients. The aim of this review is to shed light on some important and often debated issues. Hypothyroidism, unlike myxedema, is not a cause of hyponatremia (although it can be sometimes seen in conjunction with the latter) and additional investigations should be done to determine its etiology. Sodium bicarbonate is effective for treatment of hyperkalemia primarily by enhancing renal potassium elimination rather than by translocating potassium into cells. Acetaminophen can be a cause of metabolic acidosis by causing 5-oxoprolinuria. Furosemide (and sulfa containing diuretics) can safely be used in patients with an allergy to sulfa-containing antibiotics (SCA).