The following aspects can be used to determine whether an infant is sick: First, the infant may be observed in the direction of mental state, diet and sleep, and may show a lack of energy and liveliness compared to daily life, and may have a poor appetite and eat less, and may have nausea, vomiting or diarrhea. Sleep may not be good, there may be difficulty in falling asleep, wake up easily after falling asleep or sleep is not real, this is the normal life in contrast. Second, according to the symptoms of the disease to judge, with upper respiratory tract infection, respiratory system diseases may have fever, poor feeding, sneezing, runny nose, cough and other performance, if accompanied by digestive system diseases may also have nausea, vomiting, diarrhea, abdominal distension, crying and other performance. If an infant has a urinary tract disease, he or she may have a fever, increase the frequency of urination, or cry when urinating. These are the common clinical symptoms and the specific conditions that occur when observing whether an infant is ill.