Why do people become seriously ill,or die,if they go without liquid for a week o - (Dec/31/2014 )

Why do people become seriously ill,or die,if they go without liquid for a week or so ?

Our bodies are mostly water, almost all function with water so no water the end….

As merlav said above our bodies are mostly water (about 70%). Our organs and most if not all metabolic processes require water to work properly/survive. Without water you get deteriorated, dizzy,  then your organs stop working properly and if you do not supply your body with water then you finally die.