Final answer:
Hyponatremia is a lower-than-normal concentration of sodium in the body, often caused by excess water accumulation. It can be caused by various factors such as dehydration, excessive sweating, vomiting, or diarrhea.
Step-by-step explanation:
Hyponatremia is a lower-than-normal concentration of sodium, usually associated with excess water accumulation in the body, which dilutes the sodium. An absolute loss of sodium may be due to a decreased intake of the ion coupled with its continual excretion in the urine. An abnormal loss of sodium from the body can result from several conditions, including excessive sweating, vomiting, or diarrhea; the use of diuretics; excessive production of urine, which can occur in diabetes; and acidosis, either metabolic acidosis or diabetic ketoacidosis.