Sodium chloride, or table salt, supplies the electrolyte sodium to your diet. This mineral is essential for maintaining fluid balance within your cells, for contracting your muscles and for transmitting nerve impulses. It also plays a critical role in helping your digestive system absorb nutrients. Although you need a significant intake of sodium each day – up to 1,500 milligrams, or the amount contained in 3 grams of salt – most Americans consume far more than this, and ingesting too much salt can lead to adverse side effects.
Sodium is concentrated on the outside of your cells, in contrast with potassium, which exists predominantly inside your cells. The amount of sodium in the extracellular fluid helps determine the amount of water your body retains. If your sodium intake is high, your kidneys cut back on releasing water into your urine so you can balance out the excess sodium surrounding your cells. This results in an increased blood volume due to water retention. Symptoms include edema, or swelling, in various parts of your body.
Water retention can occur with high sodium intake when you are well hydrated; if you are not, however, or if you have a disorder or take medication that causes you to excrete too much water into your urine, you may experience dehydration. In this case, the extra sodium you consume still needs water to balance it out, but without sufficient water in your diet, your body may pull water from within your cells. You may then experience extreme thirst, nausea, dizziness, stomach cramps, vomiting and diarrhea as your system is unable to rid itself of excess sodium.
High Blood Pressure and Hypertension
Related to its role in maintaining blood volume, sodium can also affect blood pressure. Hormones act on your kidneys to help regulate how much sodium and water they excrete into urine. The higher the sodium level in your blood, the higher your blood volume, because your kidneys excrete less water in order to dilute the sodium in your blood. The increase in blood volume, in turn, raises blood pressure.
Ingesting too much sodium, especially over long periods of time, can lead to a chronic increase in blood pressure as your body continually battles to maintain water balance. In addition, long-term over consumption of sodium can damage the walls of your blood vessels and predispose you to developing high blood pressure, or hypertension.
Consuming too much sodium in the presence of other disorders or dietary factors might increase your risk of stomach cancer, kidney stones or osteoporosis. Chronic high salt intake can damage the lining of your stomach, making it more susceptible to infection by Helicobacter pylori, a bacterium that can cause Ulcer and inflammation and lead to tumor growth. In addition, consuming excess salt can increase the amount of calcium you excrete in urine and may contribute to the development of kidney stones. This effect is also related to osteoporosis, as your body may leach calcium from your bones to make up for that lost in your urine.
Source : SFGATE