You may have been wondering why cold weather makes you pee more often than usual.
Your kidneys can make extra pee when your body needs to get rid of a substance. It’s a process called diuresis. Apart from reasons such as medications, something you eat or a health condition, another common reason for diuresis is cold weather.
Why this is happening?
It is currently thought to be caused by the fact that your blood vessels tighten as your body tries to get warm. This sends a signal to the kidneys to get rid of fluid.
How?
When blood passes through our veins and near our skin, the external cold cools the blood, which then moves through our body, lowering our core temperature. In order to maintain our core body temperature in cold weather, the body tries to keep as much blood as it can near the core, where it can stay warm. Blood vessels and capillaries in our extremities, like the fingers, toes, ears, and nose, will constrict, allowing less blood to flow through those areas.
However, when the body constricts those blood vessels, there is less space for the blood to occupy, which causes blood pressure to increase. Since the body would prefer to keep itself warm without boosting blood pressure, it will try to relieve that pressure in a different way. There is an amount of water in our blood, so the body essentially squeezes out that water to re-balance the pressure.
Source: scienceabc.com, webmd.com