There are many reasons why diuretics don’t work, such as insufficient dose of diuretic drugs, resistance to diuretics, renal failure, and low plasma protein, etc. In addition, low body fluid volume is also a reason why diuretics don’t work. 1. For patients who need to use diuretics for a long time, such as chronic heart failure, cirrhosis and ascites, if they use them frequently, they will have a certain dependence on diuretics, and they need to increase the dosage of diuretics in order to achieve better results. 2. Resistance to diuretics: long-term use of diuretics will make patients resistant to diuretics and thus affect diuresis, this situation suggests replacing the diuretic with a better diuretic effect, or mixing with other diuretics with different mechanisms of action. 3. Renal failure: When renal failure occurs, the glomerular filtration rate decreases, urine formation decreases, in this case, even if the use of diuretics is less effective, the need for blood purification or hemodialysis. Before using diuretics, it is recommended to routinely test renal function. 4. Low plasma protein: this situation is mostly seen in malnutrition, low albumin, or long-term frequent use of diuretics patients. If the plasma protein is low, the fluid in the blood vessel will also be reduced. In this case, it is recommended to transfuse albumin, because albumin can promote the blood vessel to inhale water, which will lead to an increase in the volume of intravascular content, and the use of diuretics will be more effective at this time. In addition the low volume of body fluids is also the reason why diuretics do not work. All medications should be used under the guidance of a doctor, and early medical attention is recommended if discomfort occurs.