Why Does Salt Water Help Sore Throats?

Question

I am having some trouble understanding how salt water, a simple solution, could so effectively remove the pains of a sore throat. I do believe that the answer is closely related to hypo/hyper-tonic solutions, but why is this so, and how does this work?

Answer 1

Hypertonic and Hypotonic are easily described with a cell scenario.

Imagine you have a cell with a lot more water inside, and much less water outside the cell (hypotonic), then water will move out of the cell through osmosis until there is a balanced condition (isotonic).

Now, imagine the reverse. You have a cell with a lot less water inside, and much more water outside the cell (hypotonic), then water will move into the cell through osmosis until there is a balanced condition (isotonic).

This pattern is always the same, whether it is pure water or a solution (meaning water and something else added). Just remember, the key is to determine where the higher volume (amount) of water is located (inside or outside).

For example, if you have solutes (something else) dissolved in water and you have water in the cell, if they are the same volume that would mean that the water outside of the cell is less (because of the solute taking up some of the volume). This means the cell is hypotonic and water will move outside the cell to achieve equilibrium (balance).

A sore throat is caused by excess fluids resulting in swelling in the throat. This is a hypotonic condition.

When a person gargles with salt water, the hypertonic solution (salt water) will cause water to be removed from your throat, thus relieving the pain.

Answer 2

If the salt water is hypertonic, then water will move from the cells of the throat, which presumably are swollen, out into the extracellular space. This will reduce the swelling. If the swelling is reduced, the nerves which are sending pain impulses will stop. These may be the stretch recording nerves that tell us that tissue is being stretched.

Answer 3

Yes! You are absolutely correct. When you have a sore throat, the tissue in your throat is swollen. As you are gargling salt water, you are creating a hyper tonic solution with the concentration of salt higher on the outside of the cells within the swollen tissue(your mouth) than the inside of the cells. Cells respond to this through osmosis with water leaving the swollen area, thereby reducing the swelling.