The causes of tinnitus are complex, and there are both physiological and pathological factors. The most common pathological factors are the following three: First, the hearing in the outer or middle ear fails to receive the surrounding sound, and the faint sound produced by the inner ear becomes clearly audible. Second, the inner ear is injured and loses the function of converting sound energy, and the sound volume of the faint sound produced by itself becomes stronger and can be heard even in a very noisy environment. Third, it is from the middle ear and tones outside the inner ear. For example, in some patients with kidney disease, abnormal changes in the blood vessels in the head or neck near the hearing organs of the ear as a result make the blood supply and circulation poor, and some sounds will be produced. Older people can also experience such problems due to poor blood quality from physical exhaustion. The sound produced by the poor blood flow in the blood vessels around the ear can also form tinnitus. The presence of tinnitus can also sometimes be an indication of some kind of localized pathology, such as a tumor located in the auditory nerve. Other conditions such as otosclerosis (a disease that occurs in the middle ear auditory tuberosity) and ototoxic drug intoxication can cause tinnitus to varying degrees. There are many non-pathological factors that can cause tinnitus, and it may even be caused by a small piece of stare coming into contact with the eardrum. The most common ones are overexertion, sleep disorders, noise disturbance, stress, old age and weakness, or strong mental stimulation, which can cause abnormal discharge of the auditory nerve and lead to tinnitus. A small number of people with allergies to MSG, salt, caffeine and alcohol can also be seen to have tinnitus. Modern literature shows that the vascular system of smokers is prone to narrowing, which hinders blood flow to a certain extent and leads to a relatively high incidence of tinnitus.