Most people are familiar with sodium chloride (commonly known as salt) as a kitchen ingredient, but it also has important medical uses.
Sodium chloride (NaCl), also known as salt, is an essential compound your body uses to:
- absorb and transport nutrients
- maintain blood pressure
- maintain the right balance of fluid
- transmit nerve signals
- contract and relax muscles
Salt is an inorganic compound, meaning it doesn’t come from living matter. It forms when sodium (chemical symbol “Na”) and chloride (“Cl”) ions come together to create white, crystalline cubes.
Your body needs salt to function, but too little or too much salt can be harmful to your health.
While people frequently use salt for cooking, it’s also a common ingredient in cleaning and medical solutions. Read on to see why and how salt plays a vital role in our lives.
Although many people use the words “sodium” and “salt” interchangeably, they are different.
Sodium is a naturally occurring mineral and nutrient. Unprocessed foods like fresh vegetables, legumes, and fruit can naturally have sodium. Baking soda also has sodium.
According to the American Heart Association, about
The weight of salt is about
The most common use for salt is in food. Its uses include:
- food seasoning
- acting as a natural preservative
- enhancing the natural colors of foods
- curing, or preserving, meats
- creating a brine for marinating foods
There’s also a wide variety of household uses, such as:
- cleaning pots and pans
- preventing mold
- removing stains and grease
- salting roads in the winter to prevent ice
When your doctor prescribes a treatment with salt, they’ll use the term sodium chloride. Sodium chloride mixed with water creates a saline solution, which has several different medical purposes.
Medical uses for a saline solution
| Name | Use |
|---|---|
| intravenous (IV) drips | to treat dehydration and electrolyte imbalances; can be mixed with sugar |
| saline flush injections | to flush a catheter or IV after administering medication |
| to clear congestion, reduce postnasal drip, and keep the nasal cavity moist | |
| to wash and rinse the area for a clean environment | |
| eye drops | to treat eye redness, tearing, and dryness |
| to help create mucus so you can cough it out |
It’s important to consult a doctor and only use medical saline products (excluding over-the-counter products like contact solution) as prescribed. Different types of saline solutions contain different ratios of sodium chloride to water. Saline solutions with different purposes may also contain additional chemicals or compounds.
Normal saline vs. hypotonic and hypertonic saline
Normal saline, aka isotonic saline, has a concentration of
Hypotonic saline has a lower salt concentration, while hypertonic saline has a higher concentration.
Although salt and sodium are different, salt is 40% sodium, and we get much of our sodium intake from it.
Many companies and restaurants use salt to preserve, season, and flavor their food. Since one teaspoon of salt contains about
You can limit your sodium intake by eating unprocessed foods. You may also find it easier to manage your sodium intake by making more meals at home.
The
| Age (years) | Sodium (mg/day) |
|---|---|
| 1 through 3 | 1,200 |
| 4 through 8 | 1,500 |
| 9 through 13 | 1,800 |
| 14 and older | 2,300 |
The WHO recommends an even lower amount for people 16 and older:
Low sodium diet
A doctor may suggest sticking to a low sodium diet if you’re at risk of high blood pressure or heart disease.
The American Heart Association recommends that adults with high blood pressure limit their sodium intake to
Sodium and chloride are both essential electrolytes in your body. Here are a few of the key ways your body uses them.
Nutrient absorption and transportation
Sodium and chloride play an important role in your small intestine. Sodium helps your body absorb:
- chloride
- sugar
- water
- amino acids (building blocks of protein)
Chloride, in the form of hydrochloric acid (hydrogen and chloride), is also a component of gastric juice. It helps your body digest and absorb nutrients.
Maintaining resting energy
Sodium and potassium are electrolytes in the fluid outside and inside your cells. The balance between these particles contributes to how your cells maintain your body’s energy.
It’s also how nerves send signals to the brain, your muscles contract, and your heart functions.
Maintaining blood pressure and hydration
Your kidneys, brain, and adrenal glands work together to regulate the amount of sodium in your body. Chemical signals stimulate the kidney to either hold on to water so it can be reabsorbed into the bloodstream or get rid of excess water through urine.
When there’s too much sodium in your bloodstream, your brain signals your kidneys to release more water into your blood circulation. This leads to an increase in blood volume and blood pressure. Decreasing your sodium intake can lead to less water being absorbed into the bloodstream. The result is a lower blood pressure.
For the most part, sodium chloride isn’t a health hazard, but in excessive amounts, it can irritate your:
- eyes
- skin
- airways
- stomach
Depending on the area, you can treat the irritation by rinsing the spot with plain water or getting fresh air. Seek medical help if the irritation doesn’t stop.
Excess salt
While sodium is essential, it also exists in large amounts of almost everything we eat. According to the American Heart Association, eating too much salt can increase your risk of:
- hypertension (high blood pressure)
- stroke
- heart disease and heart failure
- kidney disease and kidney stones
- water retention, which can lead to swelling in the body
- osteoporosis
- stomach cancer
Side effects of saline solutions
Healthcare professionals typically administer saline solutions via IV.
Too little sodium
Sodium deficiency (hyponatremia) is usually a sign of an underlying disorder. It can be due to:
- inappropriate antidiuretic hormone (ADH) secretion, caused by disorders that affect hormone balance or certain drugs
- excessive water intake
- prolonged vomiting or diarrhea
- use of some diuretics
- some kidney diseases
Excessive and continuous sweating (hyperhidrosis) without proper hydration is also a potential cause, especially in people who train and compete in long endurance events like marathons and triathlons.
Salt, or sodium chloride, provides an essential mineral (sodium) that our bodies use for vital functions, such as maintaining blood pressure and absorbing nutrients. We also use salt to season foods, clean household items, and address specific medical issues.
The American Dietary Guidelines suggest that adults eat less than 2,300 mg of sodium (about 5.75 grams of salt) daily. People with heart disease or high blood pressure will want to consume even less. You can do this by eating less processed foods, like cold cuts and prepackaged foods, and cooking meals at home.
Too much salt can lead to health concerns like high blood pressure, heart disease, and kidney disease. Lowering your salt intake while increasing how much potassium you get can help reduce your risk for those conditions.
