If you start to look pale andd feel sick, what is that called?

Anemia is a condition in which your body doesn't produce enough red blood cells. It's one of the most common causes of paleness. Anemia can be acute with a sudden onset or chronic and develop slowly

anxiety

Explanation:

Looking pale, blanched, pasty, or without color is a common anxiety disorder symptom, including anxiety attacks, generalized anxiety disorder, social anxiety disorder, Obsessive Compulsive disorder, and others