Why does salt help when sick? The science behind a classic remedy

November 15, 2025 •

3 min read

According to a study published in Scientific Reports, researchers found that using a saline gargle and nasal rinse could help shorten the duration of a cold. For many, this research scientifically validates a time-honored tradition and offers a deeper understanding of why does salt help when sick.

Quick Summary

Explores the scientific mechanisms of using salt for illness, detailing how it uses osmosis to reduce inflammation, thins mucus, and helps restore vital electrolytes lost from dehydration.

Key Points

Reduces Inflammation: A saltwater gargle utilizes osmosis to draw excess fluid from swollen throat tissues, reducing pain and inflammation.
Clears Mucus: Saline nasal rinses and gargles help thin and loosen thick mucus, making it easier to expel from the nose and throat.
Replenishes Electrolytes: During sickness with vomiting or diarrhea, salt helps restore the vital sodium lost, preventing dehydration and fatigue.
Fights Viruses: A salt solution can help boost the body's natural antiviral defenses by enabling cells to produce more hypochlorous acid.
Flushes Irritants: The rinsing action of saline flushes out irritants, bacteria, and allergens from the throat and nasal passages.
Supports Oral Health: Beyond illness, gargling with salt water can also help kill harmful bacteria that contribute to dental issues and bad breath.

Understanding the Healing Power of Salt

For generations, people have turned to salt for comfort when feeling unwell. From a soothing saltwater gargle for a sore throat to a saline rinse for nasal congestion, the medicinal uses of salt are widespread. Its effectiveness isn't just anecdotal; it's grounded in basic biological principles that help the body manage the symptoms of illness.

The Role of Osmosis in Reducing Inflammation

One of the most significant ways a saltwater gargle works is through osmosis. When throat tissues become inflamed and swollen from an infection or irritation, they contain a high concentration of water. A saline solution, specifically a hypertonic one (meaning it has a higher salt concentration than the fluids inside your cells), draws that excess fluid out of the swollen tissues. This fluid-balancing act helps to reduce swelling, which can alleviate the pain and scratchy feeling of a sore throat. By coating the irritated area, the saline solution creates a barrier that can help flush away bacteria, viruses, and other irritants.

Loosening and Clearing Mucus

Whether inhaled via a saline nasal spray or gargled in the throat, salt plays a crucial role in managing mucus. When salt particles make contact with the respiratory tract's mucus membranes, they have a mucolytic effect—they help break down and thin thick mucus.

Saline Nasal Sprays: By moistening the nasal passages, saline sprays help to clear congestion and wash away irritants like allergens, bacteria, and fungi. This can provide significant relief for sinus pressure and a runny nose.
Saltwater Gargles: The same principle applies to gargling. The salt solution helps loosen and break up thick phlegm in the throat, making it easier to expel. The mechanical action of gargling physically flushes away irritants, further aiding recovery.

Replenishing Lost Electrolytes

During illnesses involving vomiting, fever, or diarrhea, the body loses not only fluids but also critical electrolytes, including sodium. This loss can lead to dehydration and fatigue. While plain water is essential for rehydration, it doesn't replace the lost salts.

Consuming a salty broth or a balanced oral rehydration solution can help replenish lost sodium and other minerals. This restores the electrolyte balance needed for proper nerve and muscle function, and for maintaining blood pressure. Replenishing these vital minerals can help you feel better and recover more quickly from illnesses that cause significant fluid loss.

Boosting the Body's Natural Antiviral Defense

Recent research has shed light on another fascinating mechanism behind salt's benefits, particularly regarding viral infections. A study from the University of Edinburgh found that saltwater nose drops could shorten the duration of colds in children. The science behind this involves chloride, a component of salt. When cells in the nose and airways are exposed to the salt solution, they use the extra chloride to produce hypochlorous acid, a natural antimicrobial compound that can help suppress viral replication. This boosts the body's local defense system, helping it fight off the virus more effectively.

Comparing Different Salt Applications


Symptom	Effective Application(s)	Mechanism	Preparation & Use
Sore Throat	Gargle	Osmosis reduces swelling; flushes irritants	½ tsp salt in 8 oz warm water; gargle for 30 secs, spit out.
Nasal Congestion	Nasal Spray / Neti Pot	Thins mucus; washes out bacteria & allergens	Use distilled water with saline packets or follow home recipe.
Dehydration	Broth / Electrolyte Drink	Replenishes vital sodium and other minerals	Drink clear, low-sodium broth or a balanced oral rehydration solution.
Viral Suppression	Nasal Spray / Gargle	Boosts cells' production of hypochlorous acid	Regular use during the onset of a cold may help shorten its duration.

Conclusion

From ancient folk medicine to modern clinical studies, the benefits of salt for managing illness have been consistently supported by science. Its utility is not confined to a single ailment but spans various symptomatic relief, from easing sore throats and clearing respiratory passages to ensuring proper hydration and even suppressing viral activity at a cellular level. Salt serves as an accessible, cost-effective, and safe supportive treatment for many minor illnesses. While not a cure, incorporating these simple saline remedies can significantly improve comfort and aid recovery. Always consult a healthcare professional for persistent or severe symptoms.

For more detailed information on treating cold and flu symptoms, consider reading the Mayo Clinic's guidance on the topic: Cold remedies: What works, what doesn't, what can't hurt.

Frequently Asked Questions

For effective relief, you can gargle with warm salt water up to 2–3 times daily, especially after meals or before bedtime. Overuse can dry out your mouth, so moderation is key.

Any kind of salt will work, including standard table salt. For the most soothing effect, use fine-grained salt, as it dissolves more quickly in warm water.

No, it is not recommended to swallow the salt water, especially in large amounts. Swallowing it may cause nausea or an upset stomach, and excessive sodium intake should be avoided.

Children who are old enough to understand and perform the gargling motion correctly can use this remedy. For younger children, a saline nasal spray may be a safer option to help with congestion.

Individuals with high blood pressure or those on salt-restricted diets should consult a doctor before using salt-based remedies, as even small amounts can impact blood pressure.

While salt water can help flush away and create a less favorable environment for pathogens, it does not act as a complete cure. It is most effective as a supportive measure to manage symptoms while your body fights the infection.

A simple oral rehydration solution can be made at home by mixing 1/2 teaspoon of salt and 8 teaspoons of sugar into 1 liter of clean water. Ensure you mix the ingredients thoroughly.