There are two distinct types of otalgia: Primary Otalgia - pain that originates from pathologies within the ear, Referred Otalgia - 
pain that originates from pathologies outside the ear and is referred to it.
Otalgia classification
Dizziness classification
Tremor classification
Headache classification
Otalgia epidemiology and demographics
Chronic pain classification
Concussion classification
Trigonometric functions