The nails lose their luster and flatness, become thin and brittle, and appear white horizontal lines commonly due to arsenic poisoning, arsenic has affinity with keratinized tissues of hair and nail skin, whether chronic arsenic poisoning or acute arsenic poisoning, as long as they survive more than 1 week after its poisoning, more content of arsenic can be found in the hair. Arsenic poisoning, often called arsenic poisoning, is mostly due to accidental or medicinal overdose poisoning. Poisoning by inhalation of its powder, fumes or contaminated skin during production and processing is also common. What are the examination methods of arsenic poisoning? 1.Blood biochemistry six items The blood biochemistry six items examination is a preliminary examination of human blood condition, including alanine aminotransferase, creatinine, urea nitrogen, serum glucose, triglyceride and total cholesterol. 2.Electrocardiogram The heart is excited by the pacing point, atrium and ventricle successively in each cardiac cycle, accompanied by changes in bioelectricity, and the graph of various forms of potential changes induced from the body surface through the electrocardiographic tracer is called electrocardiogram (ECG for short). ECG is an objective indicator of the process of occurrence, propagation and recovery of cardiac excitation. ECG is an important tool to help determine whether the electrical activity of the heart is normal, and it is the earliest, most commonly used and most basic diagnostic method in the diagnosis of coronary heart disease. 3.Serum arsenic The total amount of arsenic in the body of adults is 15-20 mg, which is mainly distributed in hair, nails, bones and skin, especially hair arsenic, which is meaningful for the diagnosis of arsenic poisoning. 4.Urine arsenic The total amount of arsenic in the body of adults is 15-20mg, mainly distributed in hair, nails, bones, and skin. The arsenic that enters the body is first transformed in the blood and then distributed to the tissues of the whole body, and the arsenic in the body is mainly excreted from the urine. Arsenic poisoning is related to the strong binding power of arsenic to sulfhydryl groups in the body, which inactivates a large number of enzymes containing sulfhydryl groups, thus hindering intracellular biochemical metabolism and causing the body’s antioxidant capacity to be significantly reduced.