when a person in the hospital os given fluid intravenously, the fluid is typically a saline solution with?

this was the answer i wrote for "Is NaCl permeable to a cell?"in the biology section. it kind of answers your question as well:"think what you are asking is can NaCl move in and out of a cell via diffusion (passive transport) i believe the answer is no. in a solution of water the ionic bond is broken and the Na+ and the Cl- are free in the solution and both of these must be actively transported across the cell membrane. Which is why it is important to use normal saline(a solution of salt and water which is equal in osmolarity to the human body) when give fluids directly into the body. too much salt in solution dehydrates the cells and too little salt causes the cell to swell up."  just quoting myself here

in the case of distilled water the process of osmosis(difusion of water) would move the water into the cell in an attempt to equalize the salt  concentration and in the case of the red blood cells they would swell until lysis occurs (aka the cell bursts)

Hypotonic solutions have fewer extra-cellular ions per unit volume than intra-cellular ions. Thus intracellular ions diffuse out of cells in an attempt to equalize the ionic balance.
This leaves the cells with too much water relative to the ionic content and disrupts the cellular metabolism.