Hello! Can you tell a 2-year-old child? In recent days, blood has ofte…

Hello! Can you tell a 2-year-old child? In recent days, blood has often come from the nose. There is no probing in the nose, we ventilate the apartment and walk outside, he hasn't been sick. What could cause blood to flow from the nose? Do I need to take any tests? What should I do? !!