Why do people turn pale when they're sick?

Answer 1

Paleness has to do with a decrease in blood flow (fainting/shock), reduced red blood cell numbers (anemia) or the body's response to a reduction in ambient temperature. Longterm pallor can also be a sign of a serious disease or condition (please check in with your doctor), but transient paleness is a perfectly normal result of a temporary situation like being sick with the flu.

Answer 2

The reason why people turn pale before vomiting is because the blood is draining from their face. This blood is needed elsewhere when you're vomiting, such as in the digestive system.

Answer 3

Majority of your blood goes into your stomach because the muscles are needing the blood to enact the action of vomiting.