Kidney disease patients will have the smell of ammonia or rotten apple, kidney disease patients are damaged by the kidney function, metabolic disorders, the toxins in the body can not be properly excreted out of the body, it will accumulate in the blood, the more toxins in the body accumulate. When it reaches a certain level, it will be through the patient’s respiratory system, especially urea nitrogen, through the patient’s respiratory system, through the mouth, so there is an ammonia smell. In addition, the metabolic function of the kidneys of patients with kidney disease has been damaged, it is easy to have an acid-base imbalance, and when there is acidosis, there will be a rotten apple smell. So the severity of the body odor of kidney disease patients is also related to the severity of the disease.