Your child's behavior is the best indicator of their health. A child who looks, behaves, and acts more or less normally is unlikely to be seriously ill. In general, a healthy child will have a good appetite and sleep well at night. Additionally, they will be full of energy and naturally curious about their surroundings and generally act appropriately for their age. As they grow, they will also have plenty of energy and a natural curiosity about their surroundings. Irritability, inactivity, trouble sleeping, disinterest, lack of appetite, running a fever, coughing, complaints of coldness, and more can indicate ill health in children. Since the conditions that may affect them vary so to do their visible symptoms, so abnormal behavior can be a good first clue.