Whether or not a low urea measurement is harmful depends largely on the cause of the low urea. If low urea is caused by physiological reasons such as low protein diet, drinking a lot of water and urinating a lot, there is usually no obvious harm; if it is caused by pathologic reasons such as consumptive diseases, alcoholism and chronic liver disease, it may cause damage to the body and needs to be treated according to the cause. 1. Physiological reasons: such as patients with long-term low-protein diet or drink a lot of water and large amount of urination, resulting in low urea, improve dietary structure and lifestyle habits, urea may return to normal, this situation is not obvious harm. 2. Pathological reasons: if the consumptive diseases such as tumors, or alcoholism and chronic liver disease, etc., may lead to low urea, resulting in physical damage, serious cases can be life-threatening, we need to identify the cause of the disease, and active treatment. If the patient found low urea, it is recommended to go to the regular hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.