A sinus infection, or sinusitis, occurs when the lining of the air-filled cavities in the skull becomes inflamed, typically due to a viral or bacterial infection. This inflammation causes swelling and prevents normal mucus drainage, leading to congestion and pressure. Sinusitis can cause watery eyes because the sinus and tear drainage systems share a close anatomical relationship. The irritation and fluid backup from the infection can directly interfere with the eye’s natural drainage system, resulting in excessive tearing.
The Anatomical Link Between Sinuses and Tears
The connection between the nasal passages and the eyes is established by the nasolacrimal apparatus, commonly called the tear duct. Tears produced to lubricate the eye surface drain through tiny openings in the inner corner of the eyelids (puncta). These tears travel through small channels into the nasolacrimal duct, which empties directly into the nasal cavity. This routing explains why the nose often runs during crying or excessive tearing.
A sinus infection causes the mucous membranes within the sinuses to swell significantly, which can block the tear duct system. The maxillary sinuses (beneath the eye sockets) and the ethmoid sinuses (between the eyes) are particularly close to this drainage pathway. Swelling in these areas physically compresses the nasolacrimal duct, preventing tears from flowing into the nose. When drainage is blocked, tears back up and spill over the eyelid, a condition known as epiphora.
Inflammation can also spread to adjacent tissues, directly irritating the tear ducts and contributing to the blockage. This mechanical obstruction causes the eye to remain wet, even if the body is not producing an abnormal amount of tears. Treating the underlying sinus inflammation is often the necessary step to relieve the pressure and restore the normal function of the tear drainage system.
Common Accompanying Symptoms of Sinus Infections
Watery eyes are seldom the only indication of a sinus infection and are usually accompanied by more recognizable symptoms. Facial pain and pressure are hallmark signs, often felt as a feeling of fullness around the forehead, cheeks, and eyes. This discomfort typically intensifies when the head is bent forward due to the shift in pressure within the inflamed cavities.
Nasal congestion or blockage is a consistent complaint, making it difficult to breathe through the nose. The body attempts to clear the infection, resulting in a thick, discolored nasal discharge (yellow or green). This discharge can also drain down the back of the throat, causing a persistent cough or throat irritation known as post-nasal drip.
Other common symptoms include a reduced sense of smell or taste and general fatigue. Inflammation in the maxillary sinuses, which are close to the upper teeth, can also cause a dull ache or pain in the upper jaw, resembling a toothache. While itchy eyes suggest allergies, the combination of these symptoms alongside watery eyes points specifically toward sinusitis.
When to Seek Medical Attention
Most sinus infections are viral and resolve on their own with self-care measures within a week to ten days. Medical consultation is necessary if symptoms persist for longer than ten days without improvement, as this may indicate a bacterial infection requiring antibiotics. A doctor’s visit is also warranted if symptoms initially improve but then worsen significantly, a pattern sometimes referred to as a “double sickening.”
Immediate medical attention is required if severe symptoms develop, as these can signal a rare but serious complication where the infection has spread beyond the sinus cavities. Red flags include a high fever that does not go away or a fever over 103 degrees. Severe pain or swelling around the eyes, particularly if accompanied by redness or warmth, should be checked immediately.
Any sudden changes in vision, such as blurriness, double vision, or difficulty moving the eyes, are considered urgent signs. These symptoms suggest potential pressure on the optic nerve or the spread of infection into the eye socket, requiring prompt evaluation to prevent further complications.