Drinking too much water at night, firstly, if the kidney function is normal, it will lead to increased nighttime urination and frequent nighttime visits to the toilet, which will affect rest. Second, if you drink too much water at night, you may get up the next morning with edema of the eyelids or face, and in serious cases, you may have swelling of both lower limbs, because drinking too much water will easily increase the blood volume, leading to edema. Third, if you drink too much water for patients with abnormal kidney function may aggravate the damage to kidney function, this is because the blood volume increases after drinking water, the plasma volume filtered from the glomerulus will also increase accordingly, which increases the burden on the kidneys. Finally, if you drink too much water at night without timely discharge, it may induce heart disease, because the blood volume increases after the heart will also increase the outward ejection of blood, which will increase the burden on the heart induced heart failure.