What causes nosebleeds on the left side?

Generally, left-sided nosebleeds may be related to factors such as dry nasal mucosa, mechanical injury, acute rhinitis, allergic rhinitis, and hypertension. Patients should promptly visit a正规 hospital to determine the underlying cause and receive appropriate treatment accordingly. Specific analyses are as follows:

1. Dry Nasal Mucosa

In dry environments, the mucous membranes inside the nasal cavity may lose moisture, becoming dry and fragile. This makes blood vessels within the nasal cavity more susceptible to damage, leading to nosebleeds. In such cases, no other abnormal symptoms typically occur. Using a humidifier or rinsing the nasal cavity with saline solution can help alleviate the condition.

2. Mechanical Injury

Scratching the nose, excessive nose picking, or using sharp objects to clean the nasal cavity can all cause damage to the nasal mucosa, resulting in left-sided nosebleeds. In this case, applying gentle pressure to the nostrils can help stop the bleeding and promote healing of the injured mucosal tissue.

3. Acute Rhinitis

Acute rhinitis refers to an acute inflammation of the nasal mucosa, usually caused by viral or bacterial infections. The inflammation leads to dilation of blood vessels in the nasal cavity, causing symptoms such as nasal congestion, runny nose, cough, and fever, along with possible nosebleeds. Treatment may include antiviral or antibacterial medications such as oseltamivir phosphate granules, ribavirin granules, or amoxicillin granules, as prescribed by a physician.

4. Allergic Rhinitis

Allergic rhinitis is an inflammatory response of the nasal mucosa triggered by allergens such as pollen or animal dander. When allergens enter the nasal passages, the immune system releases excessive chemical mediators, leading to nasal mucosal congestion and inflammation, which increases the risk of bleeding. Symptoms often include nasal congestion, clear runny nose, sneezing, nasal and eye itching, and occasional blood-tinged discharge. Management should include antihistamines such as loratadine tablets, cetirizine hydrochloride tablets, or ebastine tablets, under medical guidance.

5. Hypertension

Hypertension increases pressure on blood vessels, especially small ones. If the blood vessels in the nasal cavity are affected by high blood pressure, they become more prone to rupture, potentially causing left-sided nosebleeds. In such cases, antihypertensive medications such as valsartan/hydrochlorothiazide tablets, nifedipine tablets, or spironolactone tablets may be used under a doctor’s supervision.

In addition, conditions such as sinusitis, atrophic rhinitis, deviated nasal septum, or nasal polyps may also contribute. If nosebleeds persist over a long period, timely physical examinations, nasal endoscopy, and other diagnostic evaluations should be performed to identify the exact cause.