the answer to your question may not be as straightforward as you think. certainly at this time of year when furnace usage ramps up and dries out the air we expect to see more simple nosebleeds. if you think dry air might be causing this you can either try using a room humidifier or place some water-based lubricant (like ky jelly) in your nostril before bedtime. this usually will clear things up. however if you routinely take an anticoagulant (blood thinner) including aspirin or warfarin (coumadin) then you may want to get an evaluation from your health care provider about whether you're too anticoagulated. nosebleeds can be an early indicator that your medication dosage needs to be adjusted. hope this helps!
i have never had a nosebleed in my life but recently had 3 in a 2 1/2 week period. should i be concerned? i am 57. only the left nostril they stop within a few minutes no other symptoms.