Hello, Your son aged 33 has history of having neck injury some years back. Presently he is experiencing dizziness and numbness. He is suffering from post injury complications. Complications may include neural problems, compression of the vertebral artery that supplies blood to the brain. Pain, tingling, numbness or weakness that radiates down into the arm or hand should be evaluated by a doctor. You are suggested to get your son clinically examined by a GP / ENT. Left neglected the complications may worsen and lead to symptoms like feeling faint, bowel/bladder dysfunction and affect coordination or walking. He may be suffering from cervicogenic dizziness or cervical vertigo triggered by whiplash, cervical spondylosis, BPPV, etc. He should get flexion-extension X-ray of the cervical spine done, if needed he will be recommended to get done MRI scan of the neck, vertebral angiography / doppler, etc., to confirm diagnosis so that he can be treated at the earliest. At present he can take anti vertigo medicines (Vertin-16, one stat) and stay at rest. He is suggested not to do any heavy work, he should not drive. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician