Why Do Nosebleeds Happen? Understanding the Surprising Triggers Behind This Common Condition

If you’ve ever had a nosebleed out of nowhere—say, during a meeting, in the middle of the night, or while sipping your morning coffee—you’re not alone. Nosebleeds, or epistaxis, are more common than most people think. While they can look dramatic, especially when they seem to gush, most are harmless and easy to manage. Still, understanding why they happen can help you prevent them from recurring.

What Causes Nosebleeds?

Nosebleeds happen when tiny blood vessels in your nose—especially in the front part of the nasal septum—break and bleed. This area, known as Kiesselbach’s plexus, is packed with delicate capillaries that can rupture with just a little irritation.

Here are some of the most common reasons why nosebleeds occur:

1. Dry Air

This is the number-one culprit. Whether it’s winter heater air or a dry climate, dry air dries out your nasal membranes, making them more likely to crack and bleed.

2. Nose Picking or Blowing Too Hard

We all do it, especially during allergy season or when we’re congested. Unfortunately, picking or blowing your nose with force can traumatize those fragile blood vessels.

3. Allergies and Sinus Infections

Inflamed nasal passages from allergies or infections can lead to frequent nosebleeds, especially if you’re rubbing or blowing your nose a lot.

4. Medications

Certain medications like blood thinners (e.g., aspirin, warfarin), nasal sprays (especially decongestants), and even antihistamines can increase your risk. They either thin your blood or dry out your nasal lining.

5. Injury

A bump to the face or nose—whether from sports, a fall, or even rough play—can rupture blood vessels and trigger a bleed.

6. Underlying Health Conditions

Though less common, frequent or heavy nosebleeds could be a sign of an underlying issue like high blood pressure, a bleeding disorder, or even a nasal tumor. If you’re getting nosebleeds regularly or they’re hard to stop, it’s important to talk to a healthcare provider.

“Most nosebleeds are caused by environmental factors like dry air or irritation, and they usually resolve on their own,” says David Chen MD, ear, nose, and throat (ENT) specialist at PIH Health. “But if you’re experiencing frequent nosebleeds—especially if they’re heavy or hard to stop—it’s important to get evaluated to rule out more serious causes.”

When to See a Doctor

Occasional nosebleeds aren’t usually a cause for concern. But seek medical attention if:

• The bleeding lasts longer than 20 minutes
• You’re losing a large amount of blood
• They’re happening frequently (more than a few times a week)
• You’re on blood thinners or have a history of bleeding disorders
• You notice bleeding from both nostrils at once

How to Prevent Nosebleeds

Prevention often comes down to simple daily habits:

• Use a humidifier to keep indoor air moist
• Apply a nasal saline spray or ointment during dry seasons
• Avoid nose picking, especially in kids
• Be gentle when blowing your nose
• Stay hydrated and avoid excessive use of decongestant sprays

Bottom Line:

Nosebleeds are often more annoying than alarming, but paying attention to your environment, habits, and overall health can make a big difference. And when in doubt, don’t hesitate to get checked out.

To find a doctor, go to PIHHealth.org/Doctors

David Kuan Chen MD

Dr. Chen had a fascination with medicine early on in his childhood, as both his father and grandfather were family doctors. “I have always known that I would go into medicine since I was in kindergarten. I saw firsthand how my father and grandfather’s work impacted the lives of those in our community on a daily basis” states Dr. Chen. “I enjoy the ability to improve my patients' lives by allowing them to hear, breathe and speak better. I am fortunate to specialize in a field where tangible results can make a difference in the patient’s daily life.” Outside of work, Dr. Chen has a fascination with food and says people are often surprised by how much he can eat. His favorite restaurants are Korean BBQs and Seafood Buffets. With such a great appreciation for food, comes a responsibility to remain active. He loves hiking, cross-country running, combat workouts, kayaking and biking to name a few. Dr. Chen loves the outdoors and appreciates all that mother-nature has to offer.

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