The most common seasoning that people put on their food is sodium chloride or table salt. The human body needs salt for many of its functions such as maintaining the right fluid balance, absorbing and transporting nutrients, maintaining blood pressure, transmitting nerve signals and for the contraction and relaxation of muscles. Saline solution is used in many medical applications.

In chemistry, a solution is a homogeneous mixture containing two or more substances in which a solute is the substance that is dissolved in a solvent. Saline solution is sodium chloride at 0.85 to 0.9 added to and dissolved in 100 mL of purified water.

Normal saline is isotonic to your body fluids, meaning that it is in the same concentration that naturally occurs in the human body. You can make your own saline solution with ordinary table salt and water. Choose table salt that is without iodine. Use distilled water so that it is purified and better than regular tap water.

Dissolve 1 teaspoon of salt per 1 cup or 8 fluid ounces of distilled water. If you want a sterile solution, you simply dissolve the salt in boiling water, and then you can use it for wound care. Make certain to place a lid on the container you will store the saline solution in so that no bacteria can be introduced to it.

Note that commercial contact lens solution has added buffers to be gentle to your eyes, and this recipe doesn't have buffers.

Sodium chloride solution for intravenous use is normal saline. When someone has been sick with influenza or a stomach virus, they often become dehydrated from not drinking enough fluids and having bouts of vomiting and diarrhea. The saline solution in an IV form is administered through a vein to re-hydrate the body in a hospital or other medical office.

Since saline solution is a sterile formula, it is used in any medical setting to flush out a catheter or IV after medication is administered to a patient. It serves as a sort of cleaning and sterilizing agent in this capacity when it is an injectable form.

Saline solution has many applications in the world of medicine. It can be used to clean wounds, in an IV drip for dehydration and electrolyte imbalances and to flush catheters or IVs. Saline solution is often recommended by doctors to use as nasal drops or a nasal irrigation to clear congestion, keep the nasal cavities moist and reduce postnasal drip due to colds or allergies. Eye drops often contain saline solution to treat red eyes, dryness or tearing that can be a side effect of the common cold. Saline solution can be used as an inhaler to help create mucus and allow you to get rid of it by coughing it out.