Benign Paroxysmal Positional Vertigo (BPPV): This condition is characterized by brief, episodic vertigo triggered by head movements, which matches the patient's symptoms. The recent cold could have led to Eustachian tube dysfunction, potentially causing inner ear issues that might precipitate BPPV. However, BPPV typically doesn't cause hearing loss or tinnitus, making this less likely than initially thought.

Labyrinthitis: Given the patient's recent cold and the development of vertigo, tinnitus, and hearing loss, labyrinthitis is a plausible diagnosis. It involves inflammation of the inner ear, which could be post-viral, fitting the timeline of the patient's illness.
Vestibular Neuritis: This condition, often post-viral, affects the vestibular nerve and can cause vertigo, nausea, and balance problems. While it doesn't typically cause hearing loss or tinnitus, the proximity to the recent cold and the match with some symptoms make it a consideration.

Stroke or Cerebellar Infarct: Although rare in young individuals, a stroke can present with sudden vertigo, hearing loss, and tinnitus. It's crucial to rule out this life-threatening condition, especially given the acute onset of symptoms.
Multiple Sclerosis (MS): MS can present with a wide range of neurological symptoms, including vertigo, hearing loss, and tinnitus, especially in the context of a recent viral illness that might trigger an MS relapse.
Acoustic Neuroma: A benign tumor on the nerve connecting the inner ear to the brain, which can cause hearing loss, tinnitus, and balance problems. Early detection is crucial for effective management.

Meniere's Disease: Characterized by episodes of vertigo, hearing loss, tinnitus, and ear fullness. It's less likely given the patient's age and the acute onset of symptoms without a history of similar episodes.
Autoimmune Inner Ear Disease: A rare condition where the immune system attacks the inner ear, leading to hearing loss, vertigo, and tinnitus. It's a diagnosis of exclusion and might be considered if other causes are ruled out.
Syphilis (Otosyphilis): A rare cause of hearing loss and vertigo, especially in the context of congenital syphilis or late-stage acquired syphilis. Given the patient's age and lack of medical history, this is less likely but should be considered in a comprehensive differential diagnosis.

Audiometry: To assess the extent and nature of hearing loss.
Electronystagmography (ENG) or Videonystagmography (VNG): To evaluate vestibular function.
Magnetic Resonance Imaging (MRI): Especially to rule out acoustic neuroma, stroke, and MS.
Blood Tests: To check for infections (like syphilis), autoimmune markers, and inflammatory markers.
Vestibular Evoked Myogenic Potentials (VEMP): To assess the function of the otolith organs and the vestibular nerve.