I have a sudden urge to urinate as per bladder dairy i pee 3.5l per day and my endocrinologist is saying that since you pee more than 850ml per urinate that's why urgency is caused if you take treatment for polyuria the urgency will vanish thistrue?

Voiding above 3 liters a day without polydipsia (drinking a lot) is called polyuria and the etiology of this problem needs to be diagnosed. Rarely, a man holds more than 400 cc if he can find a restroom. Of course, with a bladder volume of 750 cc the urgency is the rule and you wish to empty your bladder as soon as possible. Yes, you need to be treated for the polyuria, not the urgency.

The cause of your polyurea is to be found and when that is treated your output will normalize as will your frequency and urgency