The ringing in ear can be due to various causes like :
1) A buildup of earwax.
2) Medicines, especially antibiotics or large amounts of aspirin.
3) Drinking an excessive amount of alcohol or caffeinated beverages.
4) Ear infections or eardrum rupture.
5) Dental or other problems affecting the mouth, such as temporomandibular (TM) problems.
6) Injuries, such as whiplash or a direct blow to the ear or head.
7) Injury to the inner ear following surgery or radiation therapy to the head or neck.
8)A rapid change in environmental pressure (barotrauma).
9)Severe weight loss from malnutrition or excessive dieting.
10) Repeated exercise with the neck in a hyperextended position, such as when bicycle riding.
11)Blood flow (vascular) problems, such as carotid atherosclerosis
, AV malformations, and high blood pressure
12)Nerve problems (neurologic disorders), such as multiple sclerosis or migraine headache
13) Acoustic neuroma
16) Meniere's disease.
18) Thyroid disease
The ear was is the most common and you should get it checked with the ENT doctor.The relevant investigations like ct scan, mri brain, blood counts etc may be advised to find the exact cause.
The treatment is directed according to the underlying cause.