How do IV Fluids Help Dehydration?

Art & Research: Parisa Boukani

Further Reading Literature: Parisa Boukani


Water is necessary for human survival, as it is involved in every biochemical reaction in every cell of our bodies. We get water from drinking fluids and the breakdown of nutrients gained from eating food. In fact, water accounts for almost 60% of our overall weight (Cleveland Clinic & Lippincott Nursing). 

Breakdown of Fluid Compartments in our Body

The body's overall water gets stored in two major compartments: intracellular compartment and extracellular compartment. All of the compartments are linked and will work together to maintain a homeostatic environment in our body (Cleveland Clinic &

Homeostasis in the Body

One way the body can maintain homeostasis (stability) is through osmosis. Osmosis is defined as the net movement of water molecules across a cell membrane from a higher concentration of water (low solute) to a lower concentration of water (higher solute). A solute is a solid that has been dissolved in a liquid (the solvent). It does this passively, meaning no energy is required from the cell to do this (Biology Online).

Symptoms of Dehydration

Dehydration occurs when your body does not have enough water. In other words, dehydration occurs when water loss exceeds water intake. Extreme thirst, headaches, and rapid heart rate are all indicators of severe dehydration. A lack of water in the body can cause dry lips, tongue, and blotchy skin. People can also produce less urine than usual (less than four times per day), resulting in more concentrated urine that is dark yellow and has a strong odor (Cleveland Clinic).

Causes of Dehydration 

Dehydration can be caused by a variety of reasons. This might occur if the person is ill (fever, vomiting, diarrhea) or if they exercise excessively without drinking enough fluids. It can also be caused by surgery, particularly when the patient is unconscious for an extended period of time which leads to fluid loss. Dehydration can also occur in pediatric/adult cancer patients or terminal care patients who do not consume enough fluids orally (Cleveland Clinic).

IV Fluids

A person then requires intravenous fluids (IV fluids) to help prevent or treat dehydration and electrolyte imbalances. There are three types of IV fluids that can be administered: Isotonic, Hypotonic, and Hypertonic (Cleveland Clinic).


Isotonic means that the fluid inside and outside of the cells are equal and that the cells will neither shrink nor swell. Thus an isotonic IV solution has the same concentration of solutes as blood and the IV fluid will replenish the cells without changing the shape of the cells (Cleveland Clinic & Osmosis).


A hypertonic IV solution has a higher solute content than inside of the cells, causing fluid to exit the cell when administered and the cell to shrink. This leads to a decrease in body fluid levels. (Cleveland Clinic & Osmosis)


When a hypotonic IV solution is given, fluid moves from the bloodstream (lower solute concentration) into areas of higher solute concentration. The cells expand, resulting in an increase in the total body fluid volume (Cleveland Clinic & Osmosis).

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