The cause of earache The most important of the ear diseases is earache. Earache can be caused by blisters on the ears, pus in the ears, blockage of dirt or foreign objects, smoke by ants, and ear infections. Earache can also be caused by nasal congestion, runny nose, and runny nose. Sore throat and swelling of the tonsils are also common. Ear pain can be diagnosed and treated