Your body needs sodium to maintain fluid balance and transmit nerve messages. While your body works to maintain tight control over its sodium level, you can sometimes lose too much sodium via sweat or due to illness. Low sodium can have life-threatening effects if left untreated. Seeking medical attention before the problem becomes severe can help keep your body functioning optimally.
As the main filters of your body, your kidneys detect how much sodium is in your blood and excrete the excess via your urine. A normal sodium level is between 135 and 145 milliequivalents per liter of blood, according to MayoClinic.com. When your sodium levels drop below 135 milliequivalents per liter, you may begin to experience adverse symptoms.
Your Body and Hyponatremia
Sodium is responsible for maintaining fluid balance in your body, which helps to regulate your blood pressure. Sodium in your blood attracts water, maintaining more sodium outside your cells than in. This is why you can feel bloated after a salty meal -- the excess sodium makes you retain water. When you lose too much sodium, water moves into your cells because your blood does not have enough sodium to attract water. This makes your cells swell with fluid. The effect is like putting too much air in a balloon. Eventually your cells can burst if they become too full. While you may not notice the immediate effects of swelling, brain cells that swell can cause you to start experiencing symptoms of hyponatremia, a condition where your sodium levels are too low.
Low Sodium Symptoms
If low sodium is not corrected, you will experience symptoms that may progress to severe. At first, you can experience fatigue, headache, irritability, appetite loss, muscle weakness, muscle spasms and nausea. As your sodium levels continue to drop, symptoms can include changes in your mental status, including confusion, hallucinations and loss of consciousness. Extremely low sodium levels can cause you to slip into a coma, which can lead to permanent brain damage. Additional complications include brain herniation or brain swelling that results in death.
You can lose excess sodium if you engage in an extended workout session and sweated heavily or have been ill with diarrhea or vomiting, which can cause you to lose excess fluid. Hyponatremia doesn't results from a typical 30-minute workout, but can occur from prolonged, intense activity such as when running a marathon. Prevent hyponatremia by replenishing your body with electrolytes, including sodium, during a workout or when you’re feeling ill. Sports drinks and electrolyte replacement fluids available at most drugstores and pharmacies can help you replace lost sodium. If you are exercising intensely, such as more than an hour or in intense heat, opt for a sports drink over plain water, recommends MayoClinic.com.
Rachel Nall began writing in 2003. She is a former managing editor for custom health publications, including physician journals. She has written for The Associated Press and "Jezebel," "Charleston," "Chatter" and "Reach" magazines. Nall is currently pursuing her Bachelor of Science in Nursing at the University of Tennessee.