Okay, so this was originally a response to someone on Discord, but it got so lengthy that I thought I'd just dump it here instead. Hope this helps.
For context:
I get nosebleeds primarily from dry air. If you get them for a different reason, then I don't know how to help you, but perhaps you could offer some tips of your own.
Here are my strategies:
(i) Stay hydrated! The best thing you can do is to make sure you're getting enough water. Pale yellow pee, people.
(ii) If you notice you always get nosebleeds out of the same nostril, sleep with your head to the side with that nostril on the bottom. For me, this makes it so that that airway won't open too much. I don't really know how else to describe it other than you might be able to tell the difference when you swallow — if I can hear air rushing through my right ear, then I know I'm at a higher risk of a nosebleed. This feeling is more pronounced if my head is to the left than to the right, so I always sleep with my head to the right.
(iii) Make sure you're breathing humid air, if possible. This sounds gross, but I like to sleep with my nose under the bedsheet. Usually I sleep with my entire head under the bedsheet, and this makes it so that I'm always breathing in humid air throughout the night, which is crucial to lessening nosebleeds. This helps even more than a humidifier, although I do also run a humidifier for most of the winter. The vast majority of my nosebleeds occur soon after waking up.
(iv) Don't blow your nose hard unless you have a cold. In 2016, a lot of my nosebleeds would start because I blew my nose. Then this one annoying teacher would tell me to stop shoving crayons up my nose. If you're already congested, you can generally get away with blowing your nose, because the mucus in there is clogging up the passageway for blood to get out (or at least, that's how it feels). I will always stop blowing my nose when congestion is getting better so that I won't accidentally start a nosebleed.
(v) Be careful when bending down, and if possible, try to kneel down rather than bend at the back. Not only is this good advice for avoiding nosebleeds, since gravity won't be sending blood flow to your face, but it's just good advice in general, since it's worse for your back to bend down like that (or at least it is for mine, and for everyone else I've talked to). Don't bend down too suddenly.
(vi) Stay away from direct airflow from air conditioners and heating vents. These often blast very dry air out of them, and I've had nosebleeds that I think would have been prevented if I hadn't been working under a heating vent. Don't take big breaths of air through your nose when you're near these or outside in the cold.
I've been putting these strategies into practice since around 2017, and each fall from 2018–2021 I've had one nosebleed on the day they turned on the heat for the first time at home or in the college dorms. Then I had none at all in 2022, and two nosebleeds a few days apart in March 2023. I think one of these was from working under a heater and not drinking enough water, and the other was because I got really excited when someone asked me about time zones and DST. But at time of writing, I haven't had a nosebleed since 2023-03-11.
For context:
I get nosebleeds primarily from dry air. If you get them for a different reason, then I don't know how to help you, but perhaps you could offer some tips of your own.
Here are my strategies:
(i) Stay hydrated! The best thing you can do is to make sure you're getting enough water. Pale yellow pee, people.
(ii) If you notice you always get nosebleeds out of the same nostril, sleep with your head to the side with that nostril on the bottom. For me, this makes it so that that airway won't open too much. I don't really know how else to describe it other than you might be able to tell the difference when you swallow — if I can hear air rushing through my right ear, then I know I'm at a higher risk of a nosebleed. This feeling is more pronounced if my head is to the left than to the right, so I always sleep with my head to the right.
(iii) Make sure you're breathing humid air, if possible. This sounds gross, but I like to sleep with my nose under the bedsheet. Usually I sleep with my entire head under the bedsheet, and this makes it so that I'm always breathing in humid air throughout the night, which is crucial to lessening nosebleeds. This helps even more than a humidifier, although I do also run a humidifier for most of the winter. The vast majority of my nosebleeds occur soon after waking up.
(iv) Don't blow your nose hard unless you have a cold. In 2016, a lot of my nosebleeds would start because I blew my nose. Then this one annoying teacher would tell me to stop shoving crayons up my nose. If you're already congested, you can generally get away with blowing your nose, because the mucus in there is clogging up the passageway for blood to get out (or at least, that's how it feels). I will always stop blowing my nose when congestion is getting better so that I won't accidentally start a nosebleed.
(v) Be careful when bending down, and if possible, try to kneel down rather than bend at the back. Not only is this good advice for avoiding nosebleeds, since gravity won't be sending blood flow to your face, but it's just good advice in general, since it's worse for your back to bend down like that (or at least it is for mine, and for everyone else I've talked to). Don't bend down too suddenly.
(vi) Stay away from direct airflow from air conditioners and heating vents. These often blast very dry air out of them, and I've had nosebleeds that I think would have been prevented if I hadn't been working under a heating vent. Don't take big breaths of air through your nose when you're near these or outside in the cold.
I've been putting these strategies into practice since around 2017, and each fall from 2018–2021 I've had one nosebleed on the day they turned on the heat for the first time at home or in the college dorms. Then I had none at all in 2022, and two nosebleeds a few days apart in March 2023. I think one of these was from working under a heater and not drinking enough water, and the other was because I got really excited when someone asked me about time zones and DST. But at time of writing, I haven't had a nosebleed since 2023-03-11.