What Is Thirst? | WIRED

“There are only a couple of things that are so important for your body that there’s a completely innate drive to get it if you fall into deficiency,” Knight said. “Oxygen, food, water, and sodium.”

However, animals like us do not experience salt desire as a powerful, controlling drive as we do with oxygen, food, and water. Sensors signal salt levels to the brain; in addition to the OVLT and SFO, sensors in the heart detect the stretching of atria and ventricles. But there is no analogous salt…