Children experiencing nasal congestion due to a cold is mainly because of the congestion and swelling of the nasal mucosa, coupled with an increase in nasal secretions, which leads to the blockage. There isn't a specific effective treatment for children's nasal congestion like there is for adults in the ENT field, which uses medications that quickly shrink the nasal mucosa. These medications can have significant side effects for children, potentially affecting the nasal blood vessels and the normal state of the nasal mucosa. Therefore, if a child is experiencing nasal congestion, it is recommended to visit a hospital where the doctor can provide specific treatment according to the child's condition. Parents should not use adult decongestants on their children without professional advice.