What diseases might unilateral nosebleeds indicate?
Nov 27, 2025
Source: Cainiu Health
Dr. Lu Cheng
Introduction
Unilateral epistaxis may be a sign of various diseases, commonly including nasal mucosal inflammation, deviated nasal septum, nasal vascular malformations, hypertension, and nasal tumors. When the nasal mucosa is infected by bacteria or viruses, inflammation occurs, leading to mucosal congestion, swelling, and increased fragility. Even minor irritation can cause mucosal damage and bleeding, often accompanied by symptoms such as nasal congestion, rhinorrhea, and nasal itching.
Unilateral nosebleeds may be a sign of various diseases, commonly including nasal mucosal inflammation, deviated nasal septum, nasal vascular malformations, hypertension, and nasal tumors. The details are as follows:
1. Nasal mucosal inflammation: Bacterial or viral infections can cause inflammation of the nasal mucosa, leading to congestion, swelling, and increased fragility of the mucosal tissue. Even minor irritation may result in mucosal damage and bleeding. This is often accompanied by symptoms such as nasal congestion, runny nose, and nasal itching. When the inflammation occurs predominantly on one side, it frequently leads to unilateral nosebleeds.
2. Deviated nasal septum: When the nasal septum is displaced toward one side, the mucosa at the deviated site is chronically exposed to airflow or dust irritation, causing it to become dry and fragile, thus prone to rupture and bleeding. Unilateral nosebleeds tend to recur and may be accompanied by one-sided nasal obstruction and headaches, with symptoms possibly worsening during bending over or lowering the head.
3. Nasal vascular malformation: Abnormal development of blood vessels in the nasal cavity may lead to malformed vascular clusters. These vessels have thin walls and are susceptible to rupture and bleeding. Bleeding is typically unilateral and may occur suddenly, ranging from mild to severe. Some patients may not experience other obvious nasal symptoms, with unilateral nosebleeds being the primary manifestation.
4. Hypertension: A sudden rise in blood pressure increases stress on the blood vessels in the nasal cavity, making them more likely to rupture and bleed. This usually presents as unilateral nosebleeds and is often associated with dizziness and headaches. The risk of epistaxis is particularly higher during emotional excitement, sleep deprivation, or straining during bowel movements due to blood pressure fluctuations.
5. Nasal tumors: Benign or malignant tumors in the nasal cavity (such as nasopharyngeal fibroangioma or nasal cancer) may invade surrounding blood vessels, resulting in unilateral nosebleeds. Bleeding from benign tumors tends to be intermittent, while malignant tumors may also present with progressively worsening unilateral nasal obstruction, bloody nasal discharge, reduced sense of smell, facial numbness, and other symptoms—requiring high vigilance.
When experiencing unilateral nosebleeds, one should first maintain a forward-leaning, head-down posture and apply pressure to the nostrils to stop the bleeding, avoiding tilting the head backward to prevent blood from flowing into the throat. If nosebleeds occur frequently, involve heavy bleeding, or are accompanied by other symptoms, prompt medical evaluation is necessary.
