Why Is Sodium Level Important In Humans?

Sodium is a mineral essential for the proper functioning of your body. It affects fluid balance, nerve and muscle function, and can also impact your blood pressure. Your kidneys play a vital role in controlling your sodium level. Keeping your sodium at optimal levels keeps your body functioning properly and helps avoid potential health problems.

Cell Membrane Potential

Sodium is one of the main minerals in extracellular fluid, while potassium is the main mineral inside of cells. The concentration difference between these two minerals inside and outside of cells allows for the proper electrical gradient across cell membranes, which facilitates nerve impulse transmission and muscle contraction. According to the Linus Pauling Institute, regulating the sodium and potassium concentration gradients is so important that approximately 20 to 40 percent of your resting energy expenditure is dedicated to this process.

Fluid Control

Different hormones act on your kidneys, allowing them to regulate sodium levels and also affecting your body's fluid levels. If sodium levels drop too low, aldosterone, a hormone released by your adrenal glands, helps conserve sodium. When sodium levels increase or become too high, aldosterone is not released and excess sodium is excreted in the urine. If your body cannot regulate excessive sodium intake, your fluid volume increases, leading to higher blood pressure and an increased risk of other cardiovascular problems.

Recommendations

Your body can regulate its sodium levels even with very little salt intake. Most Americans consume more sodium than is recommended, with the majority coming from processed foods and restaurant meals. The Harvard School of Public Health recommends limiting sodium intake to less than 2,300 mg each day. Individuals with high blood pressure or those at risk for high blood pressure should consume less than 1,500 mg of sodium each day. Adults over age 40, African Americans and those with even slightly elevated blood pressure are considered at risk for high blood pressure.

Considerations

Many factors can influence your sodium levels, including recent trauma, shock, medications or consuming too much or too little fluids. Fluid loss from diarrhea, excessive sweating and vomiting may also cause sodium levels to drop. If you are concerned about your sodium levels, talk to your doctor or health-care provider. Your doctor may recommend a blood sodium test if signs of a sodium imbalance are present.