<s>[INST] I get random nose bleed through my left nostril only...my blood pressure is normal when this happens...I have sinus problems...this mostly happen when I m exposed to strong chemical smells, perfumes or after i shower and start sneezing ....I don t get headaches or feel ill when this happens...just pressure on my forehead and at the bridge of my nose. What do you think could be some possible diagnosis? [/INST] Hello, I am unable to understand if the nose bleeds and the sinus problems happen together or are unrelated to each other. If they happen together, then it may be due to rhinosinusitis that you develop once you get exposed to string chemicals. If you get any rashes on contact to chemicals, then a type IV hypersensitivity is likely that can be proven NOT on blood tests but patch tests. If you don't get rashes, then you have (possibly) a hyperresponsive airway that can be better understood using a pulmonary function test using methacholine challenge. This allows us to understand whether you have a degree of asthma. The sinuses need to be viewed using a CT scan to ensure there are no other problems. Thanks. </s>