An essential mineral and electrolyte, sodium plays an important role in your health. It helps control your blood volume and pressure, regulates kidney function and aids in nutrient absorption. Sodium also plays a role in the function of your muscles, including the muscle tissue that makes up your heart. Consuming a small amount of sodium each day promotes healthy muscle function, while high or low levels of sodium in your system negatively affect your muscles.
Role of Sodium in Muscle Function
Sodium plays a role in communication between your nervous system and your muscle tissue to control muscle movement. Before a muscle contraction occurs, sodium rushes into your nerve cells, triggering the transmission of a small electrical signal. When your muscles sense this signal, your muscle fibers shorten and contract. Sodium's role in skeletal muscle contraction supports your posture and allows for movement, while its role in cardiac muscle contraction maintains your heartbeat.
Dangers of Too Little Sodium
Low levels of sodium in your system -- a condition called hyponatremia -- negatively affects your muscles. Too little sodium in your body prevents your nerves from communicating properly with your muscle tissue, leading to muscle weakness, as well as spasms and cramps. Hyponatremia also affects your heart muscle, increasing your heart rate. Left untreated, low sodium levels pose a serious health risk -- they can cause you to lose consciousness, suffer convulsions or even fall into a coma.
Dangers of Too Much Sodium
High sodium levels also negatively affect your muscles. You might develop muscle twitches caused by abnormal communication between your nerves and muscles, or develop an abnormally slow heart beat. Consuming too much sodium also leads to high blood pressure, which causes your heart muscle walls to grow abnormally thick and in turn increases your risk of cardiovascular disease, according to the Linus Pauling Institute.
Adequate Intake and Considerations
You need a small amount of sodium each day -- 1,500 milligrams, recommends the Institute of Medicine -- to maintain healthy nerve and muscle function, but most Americans already consume more sodium than they need each day, explains the Linus Pauling Institute. Simply following a balanced diet should provide you with the sodium your muscles need, and avoiding processed and fast foods helps prevent excessive sodium intake that can harm your muscles. If you develop symptoms of hypo- or hypernatremia, seek immediate medical attention to avoid serious health risks.