Trace element test time varies depending on the test item. The results can be obtained on the same day if the test is fast, but some items are relatively slow and may take about 1 week to obtain the results. Currently, trace element tests are mainly performed on pediatric patients, usually through hair or venous blood. The results time varies depending on the hospital and the test items. For example, for four elements such as iron, zinc, lead and copper, most hospitals above the second level can do it and the results can be ready in about 2 hours. For elements such as cobalt, selenium and iodine, results are generally available in 1-3 days. Trace elements such as manganese, silicon, boron, etc., generally need to be examined in tertiary hospitals, and usually only 1-2 days a week to do the test, and it takes 2-7 days to get the results. In addition, there are many kinds of trace elements and their deficiency can cause a series of related diseases, such as calcium deficiency in infancy can cause O-leg and X-leg, and zinc deficiency can cause lack of appetite, etc. Parents need to pay attention to them and usually need to make an appointment at the hospital before the examination.