Ache refers to a persistent, dull pain that can occur in various parts of the body. It is often less intense than sharp pain but can be uncomfortable and distracting. Common causes of ache include muscle strain, tension, or underlying medical conditions such as arthritis or fibromyalgia. There are different types of ache, including headache, backache, and toothache. Treatment options may involve rest, over-the-counter pain relievers, or physical therapy, depending on the cause and severity. Understanding the source of the ache is essential for effective management and relief.