Viruses, allergens, smoke, and pollutants can aggravate the nasal canals, causing inflammation and irritation referred to as sinusitis. According to sinusitis expert, Samuel Becker, mucosal swelling leads to the obstruction of the sinus drainage pathway, resulting in secondary bacterial sinusitis.

Your nose may become congested, or you may have post-nasal drip. These symptoms are common for a cold; however, if they persist for over 10 days or get worse after a week, you should consider a specialist.

Saline solutions are effective in combating both congestion and post-nasal drip. They flush pollutants, allergens, and germs out of the sinus tract. Both hypotonic and hypertonic saline solutions work to clear sinuses, but what is the difference? What does hypotonic and hypertonic mean?

Hypotonic vs. Hypertonic Solutions

Water travels freely across cell membranes through specialized protein-lined channels. If the concentration of solutes is not equal on both sides of the cell wall, a net movement of water will force molecules either out of or into the cell in a process called osmosis. Whether there is a hypotonic or hypertonic environment dictates the direction of movement.

Hypotonic Solutions

Hypotonic solutions are solutions that have a lower total molar concentration of solutes than that of another solution.

A lower concentration of solutes outside of the cell means that there is a higher concentration of water. In this hypotonic environment, excess water flows into the cell. If this process does not occur, cells lacking walls may swell and burst.

Hypertonic Solutions

Hypertonic solutions are solutions that have a higher total molar concentration of solutes than that of another solution.

A higher concentration of solutes outside of the cell means that there is a lower concentration of water. In this hypertonic environment, excess water flows outward from the cell. This causes the cell to shrink, and as they shrivel, they lose their function.

Solutes tend to relocate away from each other until they are evenly dispersed in a solution. In saline solutions, water molecules bond with sections of solute molecules and move them away from the highly concentrated areas. When hypotonic and hypertonic solutions mix, it initially has areas with high and low solute concentrations. The solution will reach equilibrium quickly, as water molecules work to evenly distribute solutes in a process known as diffusion.

Hypertonic and Isotonic Saline Solutions for Sinuses

Saline solutions can be hypertonic, hypotonic, or isotonic, but most rinses that are available over the counter are isotonic. These variables dictate the amount of salt that is in a solution. Saline rinses are beneficial in keeping your sinuses clear of allergens and irritants. It is comparable to a humidifier – they keep fluids moving and decrease the thickness of mucus.

The daily use of a saline solution can help prevent the inflammation and irritation responsible for sinusitis. However, not every solution is made the same. What is the difference?

Hypertonic Saline Solutions

Hypertonic saline solutions have high concentrations of salt. These solutions are beneficial for people who are congested or have a runny nose. The higher salt concentration draws excess fluid and mucus out of the sinus tract.

Hypertonic washes are useful in the colder months when the weather is cold and dry. However, many people report feeling a burning sensation when using hypertonic saline solutions. If you feel stinging or burning when using a hypertonic rinse, stop using it immediately.

Isotonic Saline Solutions

Isotonic saline solutions have lower concentrations of salt and are perfectly equalized for your body. These solutions are less effective in drawing out excess moisture and mucus, but they are excellent for providing moisture and removing allergens.

There is a relatively small difference between hypertonic and isotonic solutions, as it does not take an extreme amount of salt to change the environment.

How to Use a Saline Wash

Nasal saline irrigation improves the function of cilia, which help clear your sinuses. Regular irrigation helps prevent infections from spreading and minimizes post-nasal drip.

Isotonic and hypertonic saline solutions are available in stores, but you can also make a solution at home. To make a saline solution at home, you will need:

• 1 cup (240 mL0 of distilled water to a clean container. (Tap water can be used, but it needs to be boiled first to sterilize it.)
• 0.5 tsp (2.5 g) of salt
• 0.5 tsp (2.5 g) of baking soda

Simply mix the three ingredients and store. Homemade saline solutions are good at room temperature for up to 3 days.

To use a homemade saline solution as a nasal rinse, you should conduct the following steps:

• Fill a cleansing pot (i.e. Neti Pots), large medical syringe, or squeeze bottle with your saline solution.
• Insert the tip of your container, aimed towards the back of your head, into your nose and gently squeeze.
• The rinse should travel through the nostril and exit from either the mouth or the other side of your nose.
• Gently blow your nose.

Be sure to use only sterile materials to prevent infection. You can repeat a nasal rinse several times a day, but you should clean your bottle, syringe, or container after every use.