There is no clear instrument to detect whether formaldehyde poisoning is present in the human body, but it can be detected according to medical clinical symptoms, performance and related auxiliary examinations: 1. Typical symptoms of patients with formaldehyde poisoning include burning sensation in the mouth, esophagus and stomach and bleeding and edema in the eyes, throat, nasal cavity and oral mucosa, and even the formation of peptic ulcers and perforation of the digestive tract. 2, Patients with severe poisoning will have obvious symptoms of tachycardia, arrhythmia, palpitations, chest tightness, shortness of breath, and discomfort in the precordial area. 3. Severe poisoning will also result in irritability, drowsiness, coma, delirium, and shock. 4. Those who inhale formaldehyde will have headache, cough, runny nose, and sneezing as the first symptoms, and burning pain in the respiratory tract as the typical clinical manifestations. 5. The presence of formaldehyde poisoning is determined by the presence of abnormal liver and kidney function tests.