Prevention of ringing in the ears is related to the cause. Avoiding loud noises and high doses of aspirin can prevent some cases. Most cases cannot be prevented.
Long-term effects of ringing in the ears depend on the cause. Ringing in the ears caused by age-related hearing loss has no long-term effects besides hearing loss. The hearing loss is usually mild and is rarely bothersome. If the cause is a brain tumor, death may occur. Strokes may paralysis and speech impairments.
Ringing in the ears is not contagious and by itself poses no risks to others. If the cause is an ear infection, especially otitis media, the infection may be contagious.