The symptoms of dizziness at the beginning of smoking are mainly caused by intolerance to some components in tobacco and lack of oxygen in the brain. First, cigarettes contain nicotine, nicotine allergy or intolerance to nicotine when you first start smoking will lead to dizziness caused by brain nerve function disorders. Smoke contains carbon monoxide, which can easily reduce the ability of red blood cells to deliver oxygen, thus leading to dizziness due to lack of oxygen in the brain tissue. Third, when the patient first started smoking, there will also be a neurasthenia that affects sleep and leads to dizziness. Fourth, if the patient smoking can cause cortical excitation leading to scalp nerve vascular expansion, also appear dizziness.