Acute mastoiditis, the patient can have a history of otitis media and can have symptoms such as pus in the ear and ear pain, because poor drainage of pus in the middle ear cavity can be complicated by acute mastoiditis, and local redness and swelling can occur in the mastoid area. 2. Occipital neuralgia, there can be severe electric shock-like pain behind the ear on one or both sides, which can radiate to the head, and local pressure points can appear. 3. Local skin lesions behind the ear, such as herpes zoster in the ear, can cause severe pain behind the ear, and local skin damage such as papules and blisters can be seen on examination.