Why is my ear always ringing?

Tinnitis?: Many potential causes of tinnitis - ringing in ears - including fluid, infection. Most commonly, though, is hearing loss of life. Depending on your age, a life-time of noise can cause hearing loss, termed presbycusis. That results in a ringing, at about the frequency where you have the greatest loss. Sort of like "phantom limb syndrome" for the ears. Reco: see an ent, get a hearing test.

Many causes: There are a number of causes for ear ringing, or tinnitus. The most common cause is hearing loss, however, other causes include anything from eustachian tube dysfunction to medications to brain tumors. See an ENT and have a hearing test as an initial evaluation.