Muscle aches, also known as myalgia, are discomfort or pain in the muscles. They can occur due to various reasons, including overuse, injury, or tension. Common activities that lead to muscle aches include exercise, heavy lifting, or prolonged sitting. In some cases, muscle aches can be a symptom of an underlying condition, such as fibromyalgia or infections like the flu. Treatment often involves rest, hydration, and over-the-counter pain relievers. If muscle aches persist or are severe, it is advisable to consult a healthcare professional for further evaluation.