Red eye and runny nose on one side: what to know

A watery eye and clear nasal drainage can occur when the lining of the nose and eye reacts to pollen, dust, pets, smoke, or another irritant. Allergic rhinitis may affect the eye as allergic conjunctivitis, while a common cold can cause nasal symptoms and eye watering. Sinusitis is more likely to bring facial pressure, blocked breathing, or thicker discharge. A one-sided pattern can happen when exposure or inflammation is uneven; it does not by itself identify the cause.

Fever, cough, body aches, or recent exposure to illness may point toward a viral infection such as influenza or COVID-19. The appearance of the eye, the character of the discharge, and how quickly symptoms change help a clinician decide whether testing or treatment is needed.

Wash your hands, avoid rubbing the eye, and gently clean discharge with clean water and a fresh cloth. A cool compress may ease irritation. Reduce exposure to smoke, dust, fragrances, and known allergens; saline nasal rinsing may help nasal symptoms when performed with sterile or previously boiled and cooled water. Do not share towels or eye products. If you have fever or feel unwell, limit close contact and consider advice about respiratory infection testing. Avoid using leftover antibiotic or steroid eye drops without medical guidance.

Seek urgent eye care for moderate or severe eye pain, new blurred or reduced vision, marked light sensitivity, a visible injury or chemical exposure, swelling around the eye, or trouble moving the eye. Get prompt medical advice if discharge is heavy, symptoms are worsening, the redness does not settle, or you have a weakened immune system. A clinician can examine the eye and nose and check for a corneal problem or infection.

Could this be allergy, a viral infection, sinusitis, or an eye infection? Does the one-sided pattern change which examination or test I need? Which drops or nasal treatments are suitable for me, and what warning signs should make me return?