Excessive tear overflow is a common and frustrating symptom when you are feeling unwell. Whether dealing with a common cold, influenza, or a sinus infection, the eyes frequently become watery, red, and irritated. This phenomenon occurs due to a temporary imbalance in the eye’s system for producing and draining tears, which is closely linked to the nasal and sinus passages. Understanding this system explains why a simple illness can lead to tears streaming down your cheeks.
The Anatomy of Tear Production and Drainage
Tears are continuously produced by the lacrimal glands, located just above the outer corner of each eye, to lubricate and protect the ocular surface. This fluid is spread across the eye with every blink, forming a protective film. The tear fluid must then be drained away to prevent constant overflow.
The drainage process begins at two tiny openings, called the puncta, found in the inner corner of the upper and lower eyelids. These puncta collect the tears and channel them into small tubes called the canaliculi. The tears then move into the lacrimal sac, which is positioned next to the bridge of the nose.
From the lacrimal sac, the tears enter the nasolacrimal duct, a narrow passageway that empties directly into the nasal cavity. Tears are normally reabsorbed or swallowed once they reach the nose. This connection explains why a person may feel congested or taste tears after crying heavily.
Why Systemic Illnesses Cause Excess Tearing
The most frequent reason for watery eyes during an illness like a cold or the flu is mechanical failure of the drainage system, not increased tear production. Viral infections cause inflammation, resulting in swelling of the mucous membranes lining the respiratory tract and sinuses. This swelling, known as rhinitis, directly impacts the tear drainage pathway.
The nasolacrimal duct is surrounded by nasal tissue, and when this tissue swells, it physically compresses the duct. This compression creates a temporary blockage, preventing tears from draining into the nose. Since tears cannot pass through the constricted duct, they back up in the lacrimal sac and spill over the eyelid, causing overflow.
The widespread inflammation can also cause a minor increase in reflex tearing as the body attempts to flush out irritants. However, the primary driver is the anatomical obstruction of the nasolacrimal duct caused by nasal swelling. The symptom usually resolves once the nasal congestion and inflammation subside.
Direct Eye Irritation and Allergic Triggers
Excessive watering can also stem from direct irritation of the eye’s surface, prompting the body to produce tears as a cleansing mechanism. Allergies are a common example, where exposure to environmental triggers like pollen causes the immune system to release histamine. Histamine acts directly on the conjunctiva, the clear membrane covering the eye, leading to redness, itching, and immediate tear overproduction.
Allergies often mimic cold symptoms, featuring a runny nose and watery eyes. Unlike a cold, allergic tearing is typically accompanied by intense itching and is not due to a blocked duct. The tears produced in this scenario are meant to flush the allergen away from the eye surface.
A specific infection like conjunctivitis, commonly called pink eye, also causes direct eye irritation and excessive tearing. This condition involves inflammation of the conjunctiva, caused by viruses or bacteria. Viral conjunctivitis often produces a profuse, watery discharge, while bacterial forms may result in a thicker secretion. In both cases, the body uses tears to wash the pathogen from the eye.
When Excessive Watering Signals a Serious Problem
While most cases of watery eyes during illness are temporary, certain accompanying symptoms require medical evaluation. Excessive tearing that occurs with a sudden or noticeable change in vision should be investigated immediately. This includes blurriness, double vision, or a complete loss of sight.
Other warning signs involve the nature of the eye discharge and pain. If the eyes produce a thick, yellowish-green discharge, or if the watering is accompanied by severe eye pain, light sensitivity, or tenderness around the eye socket, it indicates a more serious infection or inflammation. If the excessive tearing persists for weeks after all other illness symptoms have cleared, it suggests a chronic blockage or underlying issue requiring diagnosis and treatment.