As sniffle season sets in, sinus infections are among the most common illnesses seen in doctors’ offices. For most people, they’re nothing more than an inconvenience and a few days of congestion, but, according to experts at the University of Alabama at Birmingham, a sinus infection can become dangerous in severe cases.

“It doesn’t happen often, but a sinus infection can spread beyond the nasal passages and into the brain,” says Elizabeth Liptrap, M.D., assistant professor in the Department of Neurosurgery. “When this happens, it can cause a brain abscess and become fatal if not treated properly.”

A brain abscess is a life-threatening fluid-filled pocket of infection in the brain, most often caused by infection elsewhere in the body. Without immediate treatment, brain abscesses can lead to brain damage and other neurological issues like seizures.

How a sinus infection reaches the brain

The sinuses are located just millimeters away from the brain, separated only by thin bone. When a severe sinus infection goes untreated or worsens, bacteria can erode through these barriers or enter the bloodstream, allowing infection to spread.

Once inside, bacteria can trigger swelling, tissue damage and a buildup of fluid, forming a brain abscess that demands urgent medical care.

Even a small abscess can lead to serious neurological symptoms and become life-threatening within days.

Warning signs you should never ignore

Jessica Grayson, M.D. FACS, associate professor in the Department of Otolaryngology-Head and Neck Surgery, warns, “Many sinus infections are viral in nature, particularly this time of year. If you have symptoms that persist beyond 7 days, please see your doctor.”

Experts urge patients to watch closely for these red flags:

• A severe or unrelenting headache that feels different from typical sinus pressure
• A fever that refuses to break
• Nausea, vomiting or extreme fatigue
• Confusion, slurred speech or personality changes
• Vision problems or weakness on one side of the body

If these symptoms appear, especially after a sinus infection, seek medical attention immediately. Timely diagnosis and treatment are crucial for preventing permanent brain damage or death.

Preventing a dangerous outcome

The good news is brain abscesses are rare, and they can almost always be prevented with early care.

• Treat sinus infections promptly rather than waiting for them to “run their course.”
• Keep nasal passages clear with hydration, humidifiers and saline rinses.
• Avoid smoke and other environmental irritants that worsen inflammation.
• Contact your physician if symptoms last longer than 10 days or return after improving.

“Brain abscesses related to sinus infections are rare, but they are medical emergencies when they do occur,” says Liptrap. “We encourage patients not to ignore persistent or worsening symptoms. Early treatment can save your life.”

This cold season: don’t brush off the signs

As winter illnesses circulate, it’s easy to dismiss sinus pain as routine. But when something feels off, when headaches grow severe, fevers linger or confusion sets in, it’s time to act.

“You are your best advocate. Know your body.” says Grayson, “Quick action could be the difference between a routine infection and a life-threatening complication.”