Can nasal mucosal erosion cause blood streaks in phlegm?

Nasal mucosal erosion may cause blood streaks in phlegm. This is mainly because the nasal cavity and oral cavity are connected; if the nasal mucosa becomes eroded, it may lead to blood-tinged sputum. However, the presence of blood in phlegm could also be due to tracheal or oral diseases. It is recommended that patients visit a正规 hospital for a comprehensive examination, determine the exact cause based on test results, and then follow medical advice for targeted treatment.