This is a GERMAN book
You are not sick - you are thirsty!
This statement of Dr. Batmanghelidj means that drinking water is so essentially important that our body cannot function without a sufficient amount of water and salt.
This comes out in different symptoms like diabetes, cancer, reduced brain functionality up to a chronical fatique - we must understand this as the cry of the body for more water!
Treating this with a light overnutrition with water and walt brings back the full functionality to your entire body-and-soul-system.