An earache or pain in the ear is medically referred to as otalgia. Pain in the ear can arise from several different sources. Any infection in the outer ear or a tumor in the outer ear will cause ear pain. Any infection or tumor in the middle ear can cause ear pain.
One of the most common causes of ear pain is temporomandibular joint dysfunction, or irritation of the jaw joint. And although the inflammation is in the joint in front of your ear, the pain will radiate directly into your ear.
Another cause of ear pain is something that we call "referred pain". If you have a bad tonsil infection or throat infection, it will often cause pain shooting to your ear. So if you have ear pain in association with throat pain, the primary cause may not be the ear, but rather the throat.
The treatment for ear pain will obviously depend upon the cause, and different causes will have different treatments.