Tinnitus: This is the most common diagnosis for buzzing in the ear, characterized by the perception of noise or ringing in the ears when no external sound is present. It can be caused by exposure to loud noise, certain medications, or age-related hearing loss.

Earwax Impaction: Excessive earwax can cause a buzzing or fullness sensation in the ear. Removal of the earwax can often resolve the symptoms.
Middle Ear Infection: Infections in the middle ear can cause buzzing or ringing, along with other symptoms like pain and fever.
Eustachian Tube Dysfunction: Problems with the Eustachian tube, which regulates air pressure in the ear, can lead to a sensation of fullness or buzzing.
Meniere's Disease: A disorder of the inner ear that affects balance and hearing, causing symptoms like buzzing, vertigo, and tinnitus.

Acoustic Neuroma: A rare, benign tumor on the nerve connecting the inner ear to the brain. Although rare, it's crucial to diagnose due to potential serious complications if left untreated.
Temporal Bone Fracture: A fracture in the temporal bone can cause buzzing or ringing in the ear, along with other symptoms like hearing loss or vertigo. Prompt diagnosis is necessary to prevent further complications.
Stroke or Transient Ischemic Attack (TIA): In rare cases, sudden onset of tinnitus can be a symptom of a stroke or TIA, especially if accompanied by other neurological symptoms.

Ototoxicity: Certain medications or chemicals can damage the ear and cause buzzing or ringing. This is less common but important to consider, especially in patients with a history of exposure to such substances.
Autoimmune Inner Ear Disease: A rare condition where the immune system attacks the inner ear, leading to symptoms like buzzing, hearing loss, and vertigo.
Vestibular Migraine: A type of migraine that affects the vestibular system, causing symptoms like vertigo, tinnitus, and buzzing in the ear.