The main causes of the left side of the brain pain in patients are to consider the following aspects. The first aspect is that if the patient shows frequent attacks of pulsating and throbbing pain on the left side of the brain, it should be considered to be caused by migraine. Migraine is a common clinical headache, and about two-thirds of patients have a family history of migraine. Migraine is mostly triggered by poor rest, sound and light stimulation, exertion, or drinking red wine or eating cheese. Thirdly, if the left side of the brain pain persists and gradually worsens, it should be considered to be caused by brain tumor or brain occupancy.