Most ringing in the ears (tinnitus) is caused by hearing loss, local ear problems, or medicine. But conditions that affect the brain or spinal cord (nervous system disorders), problems with blood flow to or near the inner ear, or tumors sometimes can cause tinnitus. In such cases, tinnitus usually:

• Develops suddenly.
• Affects only one ear.
• Occurs with additional signs of nerve damage. This may include:
  • Numbness or weakness on one side of the face.
  • Weakness or numbness on one side of the body.
  • Loss of coordination.
  • Vision changes.
  • Vertigo.
  • Vomiting.
  • Severe headache.