Middle and late stage symptoms of sinus cancer include nasal congestion, nosebleed, pain, tearing, diplopia, difficulty in opening the mouth, malignant quality and so on. 1. Nasal congestion: as the late stage symptoms of sinus cancer, nasal congestion is mostly on one side, which is intermittent and progressive at the beginning and persistent afterwards. 2. Nosebleed or bloody secretion: the number of nosebleed and the bleeding amount may be very small in the early stage, but gradually increase with the progress of the disease, which may be life-threatening in serious cases. 3. Pain: pain is mostly neuralgia, which can be an early symptom of sinus cancer, and headache occurs in the late stage when the tumor invades into orbital area or skull base. When the tumor occurs in the floor of maxillary sinus, the tumor will invade the alveolus or press the nerves of the upper teeth, thus resulting in toothache. 4. Tears: when the tumor presses the nasolacrimal duct and makes it blocked, then tears will appear. 5. Diplopia: diplopia may occur when the tumor compresses the eyeball and causes its displacement or paralysis of the eye muscles and limitation of eye movement. 6. Difficulty in opening mouth: when the tumor invades the infratemporal fossa and the pterygopalatine fossa, it can involve the biting muscle, the internal pterygoid muscle and the external pterygoid muscle, which can cause restriction of the movement of the jaw joints and thus lead to difficulty in opening mouth. 7. Malignant disease: mainly manifested as emaciation, anemia, exhaustion and so on. When the patients have the above symptoms, they should consult the doctor in time and get treatment as soon as possible.