Coughing up phlegm with blood does not necessarily indicate throat cancer. In fact, coughing up phlegm with blood refers to the presence of blood in the phlegm, which should not be confused with coughing up blood. There are many reasons for blood in the phlegm, and the first step is to rule out whether the blood is coming from the nose or the mouth. The nose is connected to the throat through the pharynx. If there is bleeding in the nose, it can also enter the pharyngeal area. Therefore, when blood is observed in the phlegm, it might be mistakenly believed to come from the lower respiratory tract. Additionally, bleeding from the oral cavity or teeth can also mix with the phlegm. After ruling out these two sources, the blood might originate from the lower respiratory tract. The common reasons for blood from the lower respiratory tract include vascular dilation, tuberculosis, and bronchial lung cancer. These conditions require medical examination to confirm. However, it is impossible to diagnose based on symptoms alone. But at least, coughing up phlegm with blood should not be immediately attributed to lung cancer, as there are many diseases that can cause this symptom.