The sensation of pressure, fullness, or pain felt beneath the eye socket is a common complaint. This discomfort arises because the eye region is a complex intersection of distinct anatomical systems, including the paranasal sinuses, the visual system, and various nerve pathways. Understanding the source requires looking beyond the eye itself, as the underlying cause often originates in neighboring structures. This article explores the most frequent reasons for under-eye pressure, detailing the mechanisms from surrounding inflammation to nervous system activity.
Sinus Inflammation and Congestion
The close proximity of the paranasal sinuses to the orbital cavity is a frequent source of pressure felt beneath the eyes. The maxillary sinuses are located directly below the eyes, and the ethmoid sinuses sit between the eyes, making them prime candidates for referred pressure when inflamed. When a viral infection, bacterial overgrowth, or allergic reaction causes inflammation, the mucous membranes lining these hollow spaces swell, which impedes the normal drainage of mucus.
This blockage leads to the buildup of fluid and trapped air within the sinus cavities, creating a physical sensation of pressure against the thin bony walls that separate the sinuses from the eye socket. In acute sinusitis, this pressure is often accompanied by a throbbing pain and facial tenderness, particularly around the cheeks and forehead. Chronic allergic rhinitis can also cause this feeling through long-term inflammation that maintains persistent tissue swelling. The ethmoid sinuses, situated deeply at the bridge of the nose, tend to cause pressure and pain felt between and behind the eyes. The resulting pressure can be accompanied by other nasal symptoms such as post-nasal drip, thick nasal discharge, and a reduced sense of smell.
Eye Strain and Ocular Conditions
Pressure felt under the eyes can be a direct result of issues within the visual system, most commonly stemming from eye strain, medically known as asthenopia. This condition develops when the eyes are subjected to prolonged, intense use, such as extended hours looking at digital screens or driving long distances. The constant effort of the ciliary muscles to maintain focus leads to fatigue, which is then perceived as a mild but persistent pressure or heavy sensation behind the eye.
Uncorrected refractive errors, such as hyperopia (farsightedness) or astigmatism, also contribute to this muscle fatigue because the eye must work harder to achieve a clear image. Reduced blinking rates during screen time can lead to dry eyes, which adds to the overall discomfort and can be misinterpreted as pressure. A more serious, though less common, direct ocular cause is elevated intraocular pressure, a symptom of conditions like glaucoma. Glaucoma involves a buildup of fluid within the eyeball that increases internal pressure, potentially damaging the optic nerve, and in its acute form, can cause severe pain and pressure around the eye.
Headaches and Referred Pain
Pressure under the eyes can frequently be a manifestation of pain originating in the nervous system or surrounding musculature, a phenomenon known as referred pain. This occurs when the brain misinterprets pain signals from one area of the head as originating in a different, nearby location. Tension headaches are a prime example, where muscle tightness in the neck and scalp can cause a dull, aching pressure that wraps around the head and often localizes behind the eyes.
Migraines are another major neurological cause, often presenting with a deep-seated, throbbing pressure or pain, typically on one side of the head, that centers around the eye. During a migraine attack, activation of the trigeminal nerve system can cause this intense periorbital pain. Cluster headaches, while rarer, are severe and almost always present with excruciating, stabbing pain focused intensely behind or under one eye, often accompanied by autonomic symptoms like tearing and nasal congestion on the affected side.
Identifying Serious Symptoms
While much of the pressure felt under the eyes is due to common, treatable conditions like sinus issues or eye strain, certain accompanying symptoms signal the need for immediate medical attention. Any sudden, severe onset of pain or pressure should be evaluated promptly. Vision changes are a significant red flag, including sudden loss of vision, double vision, or the appearance of flashes of light.
Other concerning signs involve systemic symptoms that suggest a widespread or severe infection. These include a high fever accompanied by facial pressure, which could indicate a severe sinus infection or a spread of infection into the orbital tissues. Swelling or redness around the eye that worsens rapidly, or any loss of feeling or movement in the face, requires urgent consultation to rule out potentially sight- or life-threatening conditions. If symptoms persist despite home treatment, a healthcare professional should be consulted for an accurate diagnosis.