Why Cold Weather Makes You Urinate More Often?

In winters, it is important to understand the effects of cold weather  on health and how human body responds to low temperatures and the effects of winter. Your health can be affected for good or ill depending on your response to the different aspects of winter. The best ways to stay warm in a cold climate is with the use of "inner furnace" to generate heat from within. While salad might be just the thing you want in summer, in colder months of the year, its hearty stews, soups and comfort food that just doesn't do the same thing for your appetite at other times of the year.  And this is your body's way of telling you it needs more fuel to keep warm. 

How much cold you feel and how cold you are, are not as closely related as you may imagine. While uncontrollable shivering is under the influence of your subconscious and indicates a fall in the core temperature, the feeling of cold is not a great indicator. Some people are able to tolerate the cold more than others largely on the basis of perceiving exactly the same sensations in a different way. 

On the other hand as people get older, they can become less perceptive of cold temperatures, another reason the elderly are more prone to becoming hypothermic, they just don't notice their falling body temperature. 

When we are in cold temperature, the body reduces the circulation to the extremities and skin surface, a process called peripheral vasoconstriction (peripheral = at the edges, vaso = blood vessels) so concentrating a greater volume of blood in the body core. This increases the arterial blood pressure. The body's response is to try to reduce this pressure; the kidneys reduce the volume of circulating blood by removing water to the bladder to be lost as urine. This process is known as "cold diuresis".

There are some theories, of which the most popular and accepted one is  cold diuresis. Cold-induced diuresis, or cold diuresis, is a phenomenon that occurs in humans after exposure to a hypothermic environment, usually during mild to moderate hypothermia.  According to this theory, what exactly happens is this. The below steps explained in for better understanding: 

• When your body senses cold or low temperature of environment, it constricts the blood vessels near your skin and external organs and restricts your blood to the inner core of your body to maintain its temperature.

• Thus, it causes the blood pressure to increase as there is same amount of blood in lesser volume.

• This induces negative feedback on ADH  (a vasoconstrictor) i.e. its secretion is reduced.

• Now when blood vessels in kidney get proper amount of blood (as blood vessels aren't constricted now), they sense high blood pressure and try to reduce it as soon as possible.

• So they transfer more amount of water from blood to bladder which fills the bladder more quickly and causes an urge to urinate.

• Thus, we urinate more in colder climate.

There are some more theories related to it too, but they aren't as popular. According to another theory, when we are exposed to cold weather, aquaporins  are inhibited around the body, making it impossible for water to be taken in by cells, leaving a lot more of it in the blood. Again, the body will try to balance that pressure, pulling water from the blood and storing it in the bladder.  On return to a warmer environment, circulation is restored to the periphery which reduces the volume circulating in the core, which triggers a thirst sensation so you drink, go outside in the cold again.