In mild benzene poisoning, there may be headache, dizziness, tinnitus, weakness, hallucinations and mental disorders, while in severe cases, there may be consciousness disorders, coma, muscle spasms or convulsions, respiratory difficulties, drop in blood pressure, pupil dilatation, and loss of light reflex. Benzene is also locally irritating. If it invades the eyes, it can cause inflammation of the eyes, such as tearing, photophobia, conjunctival congestion and blurred vision. Inhalation can produce choking, sore throat, increased tracheal secretions, and even laryngeal edema, spasm, or asphyxiation. Those who take it orally have obvious symptoms of gastrointestinal irritation, such as abdominal discomfort, nausea and vomiting, abdominal pain and diarrhea.