Most nosebleeds start from a small patch of blood vessels sitting just inside the front of your nose, on the wall that divides your two nostrils. This spot, called Kiesselbach’s plexus, is where several arteries meet in thin-walled, delicate branches close to the surface. It accounts for roughly 90% of all nosebleeds and is especially common in children and young adults. The causes range from something as simple as dry winter air to medications, structural issues, and occasionally underlying health conditions.
Why the Nose Bleeds So Easily
The inside of your nose is lined with a thin, moist membrane packed with tiny blood vessels. These vessels sit remarkably close to the surface, which is what allows your nose to warm and humidify the air you breathe. The tradeoff is that this tissue is fragile. Even minor irritation, a bump, or a scratch from a fingernail can rupture one of those small vessels and start bleeding.
The vast majority of nosebleeds are “anterior,” meaning they originate from the front of the nasal septum. A smaller number are “posterior,” starting deeper in the nasal cavity where larger blood vessels run. Posterior bleeds tend to produce heavier bleeding that drains down the back of the throat, and they’re more common in older adults.
Dry Air and Low Humidity
Dry air is the single most common trigger for nosebleeds. When humidity drops, whether from cold winter weather, heated indoor air, or arid climates, the nasal lining dries out and forms tiny cracks or crusts. Research published in Cureus found that breathing dry air reduces the nose’s natural moisture clearance system and increases friction against the mucosal surface. That combination damages the lining and makes the fragile blood vessels underneath more likely to break open.
This explains the classic pattern many people notice: nosebleeds that cluster in winter months or start shortly after turning on the heat for the season. Air conditioning can produce the same effect in summer. High-altitude environments, where the air holds less moisture, are another common culprit.
Nose Picking and Physical Irritation
Mechanical trauma is the other leading cause, and it doesn’t take much. Picking your nose, blowing it too hard, or rubbing it repeatedly during a cold or allergy flare can all break surface vessels. In children, nose picking is the most frequent cause by a wide margin. Frequent sneezing from allergies or a viral infection creates repeated bursts of pressure that can do the same thing, especially if the lining is already dry or inflamed.
Medications That Increase Bleeding
Several common medications make nosebleeds more likely by interfering with your blood’s ability to clot.
- Blood thinners like warfarin and newer anticoagulants reduce your body’s clotting ability overall, so even a tiny vessel break that would normally seal itself in seconds can keep bleeding.
- Aspirin and anti-inflammatory painkillers (ibuprofen, naproxen, meloxicam) block an enzyme involved in forming clots. NSAIDs are documented independent risk factors for bleeding. Taking them alongside a blood thinner raises the risk further, with studies showing a 60% increase in bleeding events when the two are combined.
- Nasal steroid sprays used for allergies can thin and irritate the nasal lining over time, particularly if the spray is aimed directly at the septum rather than toward the outer wall of the nostril.
If you’re on any of these medications and getting frequent nosebleeds, that’s worth mentioning to whoever prescribed them. The medication itself may not need to change, but additional preventive steps can help.
Structural Issues Inside the Nose
A deviated septum, where the wall between your nostrils is significantly off-center, changes airflow patterns in ways that promote nosebleeds. On the wider side of the deviation, excess airflow dries out the lining and damages the tiny hair-like structures (cilia) that keep the surface moist. Research shows more severe loss of cilia and more intense inflammatory cell buildup on this concave side. On the narrower side, the crooked cartilage or bone can physically press against the mucosa and thin it out.
Bony spurs, which are sharp ridges that sometimes develop along a deviated septum, create additional points of irritation. These structural factors explain why some people always bleed from the same nostril.
Allergies and Infections
Anything that inflames the nasal lining makes it more vulnerable. Allergic rhinitis causes swelling, increased mucus, and repeated nose blowing or rubbing, all of which stress the blood vessels at the front of the septum. Sinus infections and upper respiratory viruses do the same, with the added problem that congestion and crusting can pull on healing tissue and restart a bleed.
Chronic inflammation from ongoing allergies or frequent colds creates a cycle: the lining gets damaged, tries to heal, gets irritated again before it can fully recover, and bleeds more easily each time.
Underlying Health Conditions
Recurrent or unusually heavy nosebleeds sometimes point to a systemic health issue rather than a local nasal problem. Conditions that affect the body’s clotting system are the most important to be aware of:
- Von Willebrand disease, the most common inherited bleeding disorder, reduces the blood’s ability to form stable clots. People with this condition often have a lifelong history of easy bruising and prolonged bleeding from minor cuts in addition to nosebleeds.
- Hemophilia causes similar clotting problems, though it’s less common.
- Hereditary hemorrhagic telangiectasia produces abnormal blood vessel formations in the nose and other organs. Frequent, sometimes daily nosebleeds starting in childhood or adolescence are a hallmark.
- High blood pressure doesn’t typically cause nosebleeds on its own, but it can make them harder to stop and more severe once they start.
- Liver disease and heavy alcohol use impair the liver’s production of clotting factors, increasing bleeding risk throughout the body, including the nose.
Rarer causes include nasal tumors and other growths. These are uncommon but worth considering when nosebleeds are accompanied by obstruction on one side, facial pain, or other unusual symptoms.
Nosebleeds in Children vs. Adults
In children, the overwhelming majority of nosebleeds come from nose picking and dry air. The blood vessels at Kiesselbach’s plexus are particularly prominent and superficial in younger kids, making them bleed with very little provocation. These bleeds are almost always anterior and stop within a few minutes with simple pressure.
In adults over 50, the picture shifts. Posterior bleeds become more common, medications play a larger role, and underlying conditions like high blood pressure or clotting disorders are more likely contributors. A nosebleed that drains heavily down the back of the throat, lasts longer than 30 minutes, or involves a large amount of blood warrants emergency care, according to the Mayo Clinic.
How to Prevent Recurring Nosebleeds
Since dryness is the most common trigger, keeping the nasal lining moist is the most effective prevention strategy. Saline (saltwater) sprays or gels applied one to three times a day coat and hydrate the tissue. A humidifier in your bedroom during winter or in dry climates adds moisture to the air before it reaches your nose. The American Academy of Otolaryngology recommends both of these as first-line prevention.
Beyond moisture, a few practical habits make a real difference. Resist the urge to pick or forcefully blow your nose, especially after a recent bleed, since the healing site is fragile for several days. If you use a nasal steroid spray, aim the nozzle toward the outer wall of your nostril rather than straight at the septum. Applying a thin layer of petroleum jelly just inside the nostrils before bed can also protect the lining overnight, when dry heated or cooled air does the most damage.
For people on blood thinners or anti-inflammatory medications, these preventive measures become even more important, since your body’s ability to stop a bleed quickly is already reduced.