Salt, scientifically known as sodium chloride, is a mineral essential to life, according to the National Institute of Health. In the human body, sodium controls the volume of body fluid, helps to maintain electrolyte balance, and is an integral part of proper nerve and muscle function. Although sodium is necessary to sustain human life, consuming too much or too little salt can have negative health side effects.
Too Much Salt
The overconsumption of salt is becoming increasingly common in the American diet, according to the U.S. Department of Agriculture. The most well-known side effect of too much salt is hypertension, or high blood pressure. An excess of salt causes blood vessels to constrict, which is dangerous because the heart is required to work harder to pump blood throughout the body. Prolonged hypertension increases the risk of heart disease, heart failure, stroke, and kidney disease. Another side effect of too much salt is edema, a swelling of the body, usually seen in the hands and legs. Edema occurs when the body retains an excess of fluid in an attempt to balance out the extra sodium.
Too Little Salt
Although not as common, too little salt also can have negative health side effects. That condition, called hyponatremia, is most often caused by the use of diuretics or severe diarrhea or vomiting. In less common occurrences, hyponatremia can be caused by not eating enough salt, excreting too much sodium through prolonged exercise (such as marathon running), or drinking too much water. Early symptoms of having too little salt in the body include fatigue, confusion, headache, nausea, muscle cramps and a loss of appetite, according to the Mayo Clinic. More severe symptoms are seizures and coma.
The USDA sets the dietary guideline for salt for the average person at no more than 2,300 mg, or 1 tsp., per day. That recommendation decreases for those with existing heart problems or high blood pressure. An individual will either be put on a 1,000 mg, 2,000 mg or “NAS” ("no added salt") diet, depending on his or her specific condition. The USDA also recommends that African Americans, people with hypertension and older Americans, who all have a higher risk of hypertension, keep their sodium consumption to 1,500 mg or less per day.