What is practices in medicine designed to prevent diseases or illnesses from happening?
primary prevention
secondary prevention
tertiary prevention
quaternary prevention

The correct answer is the first option: primary prevention.

Explanation:

Primary prevention is the name given, in the field of medicine, to the practise where the intervention takes place before health effects, like illness or injury happen through measures like for example vaccination or simply doing exercise daily. The term belong to one of the three levels of prevention in the field of medicine  

loses consciousness is your real and smarter answer.

fluid balance is an aspect of the homeostasis of organisms in which the amount of water in the organism needs to be controlled, via osmoregulation and behavior, such that the concentrations of electrolytes (salts in solution) in the various body fluids are kept within healthy ranges. the core principle of fluid balance is that the amount of water lost from the body must equal the amount of water taken in.