Overhydration, also known as water intoxication, occurs when the body takes in more water than it can eliminate. This excess water dilutes the levels of sodium in the bloodstream, leading to a condition called hyponatremia. Symptoms can include headache, nausea, confusion, and in severe cases, seizures or coma. This condition is often seen in athletes who drink excessive amounts of water during endurance events, as well as in individuals with certain medical conditions. To prevent overhydration, it is important to balance fluid intake with the body's needs, especially during intense physical activity or in hot weather.