Hypernatremia is a medical condition characterized by an elevated level of sodium in the blood. This usually occurs when there is a loss of water in the body, leading to a higher concentration of sodium. Common causes include dehydration, excessive sweating, or certain medical conditions that affect water balance. Symptoms of hypernatremia can range from mild to severe and may include thirst, confusion, muscle twitching, and in extreme cases, seizures or coma. Treatment typically involves rehydrating the patient, often through intravenous fluids, to restore the proper balance of sodium and water in the body.