The normal use of essential oils does not usually cause poisoning, but if the quality of essential oils is not qualified or a few people are allergic to essential oils, the use can cause poisoning afterwards. After allergy or poisoning caused by overuse of essential oils, the patient will have the following symptoms: 1st, the patient will have a rash, itchy skin, red spots, swelling of the face, numbness of the mouth and tongue, and a series of other symptoms. Patients can also appear headache, dizziness, weakness and a series of symptoms of central nervous system damage, there are also essential oil allergy after the patient will appear cough, coughing, breathing difficulty symptoms, serious will cause asthma, leading to respiratory failure and endanger the life of patients. Secondly, after the poisoning of essential oil, some patients will also have a series of symptoms such as loss of appetite, poor appetite, abdominal distension, abnormal stool, etc.