Immediate causes of nosebleeds include trauma to the nose from an injury, deformities inside the nose, inflammation in the nose, or, in rare cases, intranasal tumors. Any of these conditions can cause the surface blood vessels in the nose to bleed.

Types of Nosebleeds

There are two types of nosebleeds: those that originate in the front of your nose, called anterior nosebleeds, and those that start in the back of it, or posterior nosebleeds. Anterior nosebleeds are very common and typically not that dangerous. These types of nosebleeds can usually be treated at home. The most common origin site of an anterior nosebleed is the septum, or the part of the nose that separates your nostrils. It contains many blood vessels that can break from a simple scratch or a blow to the face. Posterior nosebleeds, on the other hand, are much less common. These begin deeper in the nose when the nasal cavity is damaged and bleeds. Posterior nosebleeds can be dangerous; for example if blood leaks into your throat. An injury to the nose and high blood pressure are the most common causes of posterior nosebleeds.

1. Underlying Health Conditions

Liver disease, kidney disease, chronic alcohol consumption, or another underlying health condition can lower your blood’s ability to clot and therefore cause your nose to bleed. Heart conditions like hypertension (high blood pressure) and congestive heart failure can also cause nosebleeds, as can hypertensive crisis — a sudden, rapid increase in blood pressure that may be accompanied by a severe headache, shortness of breath, and anxiety, according to the American Heart Association (AHA). Colds, allergies, and frequent nose-blowing can also irritate the lining of your nose, resulting in a nosebleed.

2. Dry Air

Dry air from indoor heating or outdoor cold can dry out the lining of the nose, causing it to crack and bleed. Using a humidifier while sleeping can help relieve dryness, and nasal sprays are helpful for moistening the nostrils.

3. Foreign Objects

Nosebleeds can also occur if a foreign object is placed in the nose. This is most common among small children, who explore their world by putting objects in their mouth, nose, or ears. Examples of these items include small toys, pebbles, food, erasers, and dirt.

4. Blood-Thinning Medications

Because blood clotting is a necessary step in preventing or stopping a nosebleed, any medication that changes the blood’s ability to clot can cause a bloody nose — or make one harder to stop. Examples include anticoagulants like Coumadin or Jantoven (warfarin), the anti-platelet medication Plavix (clopidogrel bisulfate), over-the-counter drugs like aspirin, and prescription or over-the-counter NSAIDS like naproxen. Many people with the heart condition atrial fibrillation (afib), an irregular heartbeat, take anticoagulant medication to prevent blood clots from forming. And if you’ve had a heart attack, your doctor may have recommended a daily aspirin to help prevent a recurrence. Blood clots can lead to a stroke or heart attack if they travel through the blood and reach the brain or heart, but the anticoagulant medications commonly used to prevent clots carry an increased risk of bleeding.

5. Nose Picking or Scratching

Accidental injury to the blood vessels in the nostril from nose picking can cause a nosebleed. This is common in children, but also in adults who are prone to itching or scratching inside their nose.

How to Stop a Bloody Nose at Home

While sitting and leaning forward, use direct pressure to stop bleeding by pinching your nostrils shut for at least 10 minutes, breathing through your mouth.Alternatively, you can make a nose-pinching device using tongue depressors and tape.If bleeding starts again, use a nasal decongestant spray (such as Afrin, Dristan, or Vicks Sinex) to constrict the blood vessels of your nose, and again apply direct pressure to stop bleeding.

To prevent another bloody nose, use saline and topical ointments to moisturize inside your nose, but only once bleeding has stopped. And avoid picking or scratching your nose.

When to Get Help for Nosebleeds

Although most nosebleeds can be treated at home, some are severe and require medical attention. Kevin Campbell, MD, a cardiologist at Wake Heart and Vascular in Raleigh, North Carolina, says “Nosebleeds are rarely life-threatening. But under certain circumstances, such as if you’re taking blood thinners like aspirin or warfarin, nosebleeds can be quite concerning and require medical care.” In such cases, your healthcare provider may need to adjust the dose of blood-thinning medication, he says. Having more than one nosebleed a week is also a sign that you should talk to your doctor. “If nosebleeds are recurrent — whether or not you’re on blood-thinning medications — it’s reasonable to seek help from your primary care physician,” says Dr. Campbell. He adds that recurrent nosebleeds may point to other, more significant medical conditions. “You should certainly seek medical attention in an emergency room if your nosebleed lasts longer than a few minutes, or if you’re unable to stop the bleeding with direct manual pressure," Campbell says. Additional reporting by Ashley Welch