What Causes Seasickness?

Seasickness may feel like it begins in the stomach, but it actually starts in the ears!

Your sense of balance is controlled by canals filled with lymph inside the ears. Now, when you're on a ship that is rocking back and forth, the lymph rocks back and forth too, sending messages to the brain that keep changing as the position of the deck changes.

Eventually, these changing messages "overload" the brain and confuse the nervous system. This confusion produces the nausea, dizziness, sweating, and other discomforts we call seasickness.