What causes epistaxis?

What Causes Nosebleeds

Nosebleeds (epistaxis) are most commonly caused by local trauma to the nasal mucosa—particularly digital manipulation (nose picking), dry air causing mucosal desiccation, and inflammation—though systemic factors including anticoagulant medications, hypertension, and bleeding disorders can increase severity and recurrence. 1, 2

Primary Local Causes

The majority of nosebleeds originate from local disruption of the nasal mucosa, particularly in the anterior nasal septum where the Kiesselbach plexus is located 2:

• Digital trauma (nose picking) is one of the most common precipitating factors, especially in children 2
• Mucosal dryness and inflammation from dry environments, low humidity, or nasal oxygen/CPAP use causes fragile mucosa that bleeds easily 1, 2
• Nasal inflammation from colds, allergies, rhinosinusitis, or abrupt temperature changes produces hyperemic mucosa prone to bleeding 2, 3
• Intranasal drug use, including topical medication overuse or illicit drug snorting, can damage the nasal mucosa unilaterally or bilaterally 1, 2
• Nasal foreign bodies can cause localized trauma and bleeding 2
• Prior nasal or sinus surgery creates post-surgical changes that predispose to bleeding 1, 2

Medication-Related Causes

Anticoagulant and antiplatelet medications are major risk factors that increase both frequency and severity of epistaxis 1:

• Warfarin requires INR monitoring, as supratherapeutic levels significantly increase bleeding risk 1, 2
• Antiplatelet agents (aspirin, clopidogrel) cause persistent epistaxis through platelet dysfunction 2
• Direct oral anticoagulants (DOACs) have limited reversal options and increase bleeding risk 2
• Clinicians should specifically ask about recent changes in dosage or medication type 1

Systemic and Vascular Causes

Several systemic conditions contribute to epistaxis, though hypertension's role remains controversial 1, 2:

• Hypertension is associated with epistaxis (prevalence 24-64% in epistaxis patients), particularly posterior bleeding, though no definitive causal relationship exists 2, 4
• Bleeding disorders including von Willebrand disease, hemophilia, and other coagulopathies predispose to severe or recurrent bleeding 1, 2
• Chronic kidney or liver disease impairs coagulation function 1
• Hereditary hemorrhagic telangiectasia (HHT) causes recurrent bilateral nosebleeds, typically starting in childhood, with visible telangiectasias on nasal/oral mucosa 2, 4
• Atherosclerosis in elderly patients affects vascular integrity 3

Age-Related Patterns

Epistaxis follows a bimodal age distribution with distinct characteristics 2:

• Children under 10 years experience predominantly anterior bleeding from trauma and inflammation 2
• Adults 70-79 years have peak incidence, with patients over 85 having 3.24 times higher likelihood of emergency department visits 2
• Posterior epistaxis (5-10% of cases) is more common in older patients, more difficult to control, and carries higher hospitalization rates and a 30-day mortality of 3.4% 2, 4

Red Flags Requiring Further Investigation

Certain presentations suggest serious underlying pathology requiring immediate evaluation 2:

• Unilateral epistaxis with nasal obstruction, facial pain, or visual changes suggests intranasal tumors or masses 2
• Recurrent bleeding despite appropriate treatment warrants assessment for underlying conditions including vascular malformations 2
• Bilateral recurrent nosebleeds with family history should prompt evaluation for HHT 2
• Hemodynamic instability (tachycardia, hypotension, pallor) indicates significant blood loss requiring urgent hospital-level care 2

Critical Documentation Requirements

The American Academy of Otolaryngology-Head and Neck Surgery mandates documenting specific risk factors 1:

• Personal or family history of bleeding disorders
• All anticoagulant or antiplatelet medications with recent dosage changes
• Prior nasal/sinus surgery
• Nasal cannula oxygen or CPAP use
• Intranasal medication use
• Chronic kidney or liver disease
• Hypertension status (though routine acute blood pressure lowering is NOT recommended during active bleeding due to risk of end-organ ischemia) 1, 2