Failure to find a blood vessel in the hand for infusion may be caused by thin peripheral blood vessels, hypothermia, obesity, and hypovolemia. 1. Thin peripheral blood vessels: Smaller patients, such as women and the elderly and frail, have thinner blood vessels, making it more difficult to find them. 2. Hypothermia: If the patient’s environment is too cold, resulting in a drop in body temperature, it is easy to cause venous vasospasm and contraction, making it difficult to observe the venous vessels. 3. Obesity: the patient’s subcutaneous adipose tissue is thicker, which will easily lead to the venous blood vessels not showing clearly. 4. Insufficient blood volume: If the patient has vomiting, diarrhea, fever and other symptoms, he will lose body fluids and be in a state of hypovolemia, which will reduce the filling of blood vessels and then lead to thinning of blood vessels. If you can’t find the surgical vessels for infusion, it is recommended to have more experienced nurses in regular medical institutions to perform the intravenous infusion operation.