There are many reasons why patients may experience pain in the mastoid area behind the ear, and some of the more common ones are as follows: First, there are lymph nodes on the surface of the mastoid area behind the ear, which may become inflamed when the patient gets anxious and inflamed, so the patient may experience pain. Second, the patient may have a boil formation or a cyst behind the ear in the mastoid area behind the ear, and if there is an infection, the patient may also have significant pain. Third, if the patient has acute suppurative otitis media, there may be inflammation in the mastoid area, so the patient may also experience significant pain when pressure is applied. Regardless of the cause of the pain in the mastoid area behind the ear, the patient must be actively treated symptomatically so that the pain will gradually improve.