One-sided eye and nostril runniness can be confusing. This symptom, with tears from one eye and mucus from the corresponding nostril, suggests a localized response. This one-sided runniness has biological explanations rooted in the interconnectedness of facial structures. It is often a result of either an irritant or an underlying condition affecting a single side of the face.
The Connected Pathways
The lacrimal system connects the eye and nasal cavity. Tears are produced by the lacrimal glands, located above the outer corner of each eye. These tears spread across the eye’s surface, keeping it lubricated and clear of debris. After serving their purpose, tears drain through tiny openings called puncta in the inner corner of the eyelids.
These puncta lead into small canals, which then merge into the lacrimal sac. The lacrimal sac connects to the nasolacrimal duct, a narrow tube opening directly into the nasal cavity beneath the inferior turbinate. This direct drainage pathway means that any excess tears or irritants in one eye can easily flow into the corresponding nostril. This anatomical arrangement is why irritation or increased tear production in one eye often leads to a runny nose on the same side.
Everyday Reasons for Unilateral Symptoms
Common, often benign, factors cause one-sided eye and nostril runniness due to localized irritation. Allergens are a frequent culprit; direct contact with one eye, such as rubbing it after touching a pet or pollen, can trigger a localized allergic reaction. This localized exposure leads to increased tear production and nasal discharge on the affected side. Similarly, environmental irritants like dust, smoke, or even strong fumes can cause a similar one-sided response if they primarily affect one eye or nostril.
A foreign body, like an eyelash or dirt particle, entering one eye can also stimulate excessive tearing. The eye attempts to flush out the irritant with increased tear production, and these tears then drain into the ipsilateral nostril, causing it to run. Emotional crying can sometimes appear one-sided if one eye produces significantly more tears, or if the individual is lying on their side, directing tear flow primarily from one eye. Early stages of a common cold or mild viral infection might present with more prominent symptoms on one side before becoming generalized.
Medical Conditions Causing One-Sided Runniness
Several medical conditions can cause persistent one-sided eye and nostril runniness, often with distinct underlying mechanisms.
Sinusitis
Sinusitis, an inflammation or infection of the sinuses, can affect one side of the face. When a single maxillary or frontal sinus is inflamed, it can cause localized pressure and pain, alongside drainage that affects the adjacent eye and nostril. The inflamed sinus can produce mucus that drains into the nasal cavity, and the associated irritation can indirectly stimulate tear production on the same side.
Cluster Headaches
Cluster headaches are a severe headache with intense, unilateral pain, often around the eye or temple. This neurological condition is frequently accompanied by autonomic symptoms on the same side as the headache. These symptoms include lacrimation (tearing from the eye), nasal congestion, or rhinorrhea (runny nose). The exact mechanism involves the trigeminal autonomic reflex, which leads to activation of parasympathetic pathways causing these one-sided fluid releases.
Dacryocystitis
Dacryocystitis is an infection or blockage of the lacrimal sac or nasolacrimal duct on one side. This blockage prevents tears from draining properly, leading to a buildup in the eye and subsequent overflow. The infection can cause inflammation, pain, and swelling around the inner corner of the eye, with pus or mucus discharge that can drain into the nose, contributing to the one-sided runniness.
Other Causes
Less common causes include structural abnormalities within the nasal passages or sinuses, such as a deviated septum or polyps, which can obstruct drainage or irritate pathways on one side, leading to unilateral symptoms. Rarely, a growth or tumor in these areas could also exert pressure or cause irritation.
When to Consult a Doctor
Consult a healthcare professional if one-sided eye and nostril runniness becomes persistent or worsens. Additional symptoms, such as pain, fever, or facial swelling, warrant medical evaluation. Vision changes, especially with eye pain or redness, also prompt a doctor’s visit.
Discolored, thick, or bloody discharge requires professional assessment. Seek medical advice if symptoms interfere with daily activities or do not resolve within a reasonable timeframe. An accurate diagnosis from a healthcare provider is important to determine the underlying cause and ensure appropriate treatment.