A deviated septum happens when the thin wall between your two nasal passages gets pushed to one side, making one airway smaller than the other. You can get one from an injury to the nose, but most people are simply born with it or develop one gradually over time. An estimated 80 percent of people have a septum that’s at least slightly off-center, according to Stanford Medicine, though only a fraction experience symptoms severe enough to need treatment.
Born With It: Congenital Causes
The most common way to end up with a deviated septum is to have one from the start. The nasal septum, a structure made of cartilage and bone, can shift during fetal development. Pressure in the womb or the physical compression of passing through the birth canal can push the septum off its midline. In many of these cases, the deviation is so minor that a person never knows it’s there.
Some congenital deviations only become noticeable later. As you grow through childhood and adolescence, the septum grows too, and uneven growth patterns can turn a barely-there shift into something more pronounced. A deviation that caused no issues at age 10 might start affecting breathing by adulthood.
Injury to the Nose
A direct blow to the nose is the other major cause. Contact sports, car accidents, falls, and even rough play during childhood can all push the septum out of alignment. The cartilage in the septum is relatively flexible in young children, which means it can absorb some impact without permanently shifting. In adults, though, the septum is firmer, and a strong hit is more likely to cause a lasting deviation.
Not every broken nose results in a deviated septum, and not every deviated septum involves an obvious fracture. Sometimes a moderate impact displaces the cartilage without breaking bone, and the person doesn’t realize the septum has shifted until breathing problems develop weeks or months later.
How Aging Makes It Worse
A deviated septum can worsen with age. Cartilage changes over time, losing some of its firmness and shifting position as the nose continues to subtly reshape throughout life. A mild deviation that never caused symptoms at 30 can become noticeably obstructive by 50 or 60. The tissues lining the nasal passages also tend to swell more easily with age, which compounds the airflow restriction on the already-narrower side.
What It Feels Like
Many people with a deviated septum have no symptoms at all. When the deviation is significant enough to block airflow, though, the effects are hard to ignore. The most common complaint is feeling chronically congested on one side of the nose. You might notice you always breathe better through one nostril, or that congestion from a cold hits one side dramatically harder than the other.
Other symptoms include:
- Mouth breathing and snoring, especially during sleep, because the obstructed side can’t move enough air
- Frequent nosebleeds, since the airflow through the narrowed passage dries out and irritates the lining
- Recurring sinus infections, because poor drainage on the blocked side traps mucus
- Facial pain or pressure, particularly when the shifted septum presses against the side wall of the nasal cavity
- Sleep disruption, including restless sleep or symptoms that overlap with sleep apnea
These symptoms often get blamed on allergies or chronic sinusitis for years before a deviation is identified as the underlying problem.
How It’s Diagnosed
Diagnosis is straightforward. A doctor looks inside your nose using a bright light and a tool to gently spread the nostrils open. In most cases, a deviation is visible on this basic exam. If the doctor needs to see deeper into the nasal passages, a thin, flexible scope with a light at the tip can be inserted to get a clearer picture of how far back the deviation extends and whether other structures, like swollen turbinates or nasal polyps, are also contributing to the blockage.
When Surgery Becomes an Option
Most deviated septums don’t need surgical correction. Mild symptoms can often be managed with nasal sprays that reduce swelling in the lining of the passages, improving airflow without touching the septum itself.
Surgery, called septoplasty, becomes a consideration when symptoms persist despite those measures. The American Academy of Otolaryngology outlines specific thresholds: nasal obstruction that causes chronic mouth breathing, snoring, or sleep apnea and hasn’t responded to medical treatment; recurrent nosebleeds tied to the deviation; or facial pain originating from a point where the septum presses against the side wall of the nose. In some cases, a deviation that causes no symptoms on its own still needs correction because it blocks surgical access to the sinuses for other necessary procedures.
Before recommending septoplasty, a specialist will document a full exam of both nasal passages and rule out other causes of obstruction, like polyps or enlarged turbinates, that might explain the symptoms independently. The goal is to confirm the deviation is actually driving the problem, not just present alongside it.