Viral Upper Respiratory Infection (URTI): The combination of dizziness and congestion for 2 weeks could be attributed to a viral upper respiratory infection, which is common and can cause these symptoms due to nasal congestion, sinus pressure, and possible inner ear involvement affecting balance.

Allergic Rhinitis: Allergies can cause significant nasal congestion, which may lead to dizziness due to decreased airflow and increased pressure in the sinuses and Eustachian tubes, affecting the middle ear and balance.
Sinusitis: An infection or inflammation of the sinuses can cause congestion and, if it affects the sinuses near the inner ear or causes significant pressure changes, may lead to dizziness.
Benign Paroxysmal Positional Vertigo (BPPV): Although more commonly associated with positional vertigo, BPPV could be considered if the dizziness is triggered by specific head movements, and the congestion is coincidental or contributing to the sensation of imbalance.

Stroke or Transient Ischemic Attack (TIA): Although less likely, it's crucial to consider stroke or TIA, especially if the dizziness is sudden, severe, or accompanied by other neurological symptoms like weakness, numbness, or difficulty with speech.
Meniere's Disease: An inner ear disorder that can cause vertigo, tinnitus, hearing loss, and a feeling of fullness in the ear. The congestion might be unrelated, but the disease could explain the dizziness.
Multiple Sclerosis: An autoimmune disease that can cause a wide range of neurological symptoms, including dizziness. Early diagnosis is crucial for management.

Acoustic Neuroma: A non-cancerous tumor on the nerve connecting the inner ear to the brain, which can cause vertigo, hearing loss, and tinnitus. The congestion would likely be unrelated.
Vestibular Migraine: A condition that can cause vertigo, often accompanied by migraine headaches, but sometimes without the headache. It could be considered if other migraine symptoms are present.
Temporal Bone Fracture or Inner Ear Injury: If there's a history of trauma, these conditions could cause dizziness and should be ruled out, even though they are less common in the context of congestion without a reported injury.