Rarely, too much water is a problem seen in healthy adults, but occasionally observed amongst athletes who try to prevent dehydration during intense exercises. When you drink too much water, your kidneys are unable to flush out the excess water. And the sodium in the blood becomes diluted. This life-threatening condition is called hyponatremia and may cause seizures. For people with overactive bladder, drinking too much water also aggravates their symptoms of frequency, urgency, and even incontinence.