What is the term for a lower than normal concentration of sodium in the blood?

The term for a lower than normal concentration of sodium in the blood is hyponatremia. This condition occurs when the sodium level drops below the typical range, which can lead to various health issues because sodium plays an essential role in maintaining fluid balance, nerve function, and muscle function.

When the sodium concentration is lower than normal, it can result in symptoms such as headache, confusion, seizures, and in severe cases, can be life-threatening. Understanding hyponatremia is crucial, especially in contexts like exercise, where excessive fluid intake without adequate sodium can lead to this condition.

The other terms refer to different electrolyte imbalances: hypernatremia indicates an elevated sodium level, hypokalemia refers to low potassium levels, and hyperkalemia signifies high potassium levels. Each of these conditions has its own causes, symptoms, and clinical implications, thereby distinguishing them from hyponatremia.