A deviated septum can be genetic, but most cases result from a combination of inherited facial structure, birth trauma, and injuries throughout life. One study found a striking pattern: when children had a specific type of septal deformity, 21 out of 22 of their parents (both mothers and fathers) had the same type. None of the parents of children with straight septums showed that deformity. So genetics clearly plays a role, but it’s only one piece of the puzzle.
What the Research Shows About Inheritance
The septum is the wall of cartilage and bone dividing your two nasal passages. Its shape is influenced by your overall facial bone structure, which is largely determined by your genes. If your parents have narrow midfaces, prominent noses, or asymmetric facial features, you’re more likely to develop a deviation yourself.
For years, researchers believed only deviations in the back of the septum could be inherited, while deviations toward the front were caused by injury. That assumption has been challenged. A study of families with a specific anterior (front) septal deformity found a high correlation between parents and children, suggesting that at least some types of front-of-septum deviations are inherited too. The pattern held for both mothers and fathers passing the trait to their children.
That said, no single “deviated septum gene” has been identified. What you inherit is the overall geometry of your face, the growth rate of your nasal cartilage, and the structural tendencies that make a deviation more or less likely. Connective tissue disorders can also increase the risk, since they affect the cartilage and supportive structures throughout the body, including the nose.
Other Major Causes
Birth itself is a surprisingly common cause. The nose is the most protruding part of a baby’s face, and it absorbs significant compressional and rotational forces during delivery. Studies of newborns in India found septal deviations in about 20% of babies examined within two days of birth. The risk is higher for first-time mothers, prolonged or difficult labors, and larger babies where the head fits tightly through the birth canal.
Facial injuries are the other big contributor. A broken nose, a fall, contact sports, car accidents: any direct hit to the nose can shift the septum off center. These traumatic deviations tend to look different from inherited ones. Developmental deviations are typically smooth, with a gentle C-shaped or S-shaped curve. Traumatic deviations are more angular and irregular, sometimes with sharp bends or dislocated segments.
Growth itself can also worsen things. The nasal septum grows rapidly through childhood and into the teen years, then stabilizes. If there’s already a slight asymmetry from genetics or birth, that rapid growth phase can amplify it. This is one reason a deviation that caused no problems in childhood can start producing symptoms during or after puberty.
How Common Deviated Septums Really Are
Far more common than most people realize. Reported prevalence ranges from 26% to 97% depending on how strictly “deviation” is defined and what imaging is used. When researchers use CT scans, which catch even minor deviations invisible to the naked eye, rates climb as high as 86.6%. In practical terms, the majority of adults have some degree of septal deviation. Most never notice it.
Signs You Might Have One
Many people live their entire lives with a deviated septum and never know. Symptoms only appear when the deviation is significant enough to block airflow or dry out the nasal lining. The most common signs include:
- Blocked breathing on one side. This often worsens during colds or allergy flare-ups, when swollen tissue narrows the already-reduced passage further.
- Frequent nosebleeds. The narrower side dries out faster, making the tissue fragile and prone to bleeding.
- Noisy breathing or snoring during sleep. Some people find they can only sleep comfortably on one side to keep the less-blocked nostril open.
- Chronic dry mouth. When nasal breathing is difficult, you compensate by breathing through your mouth, especially at night.
- A visibly crooked nose. Not always present, but in some cases the external appearance of the nose reflects the internal deviation.
How It’s Classified
Doctors categorize septal deviations by their shape and location. The most common descriptions are C-shaped (curving to one side) and S-shaped (curving one way at the top and the opposite way at the bottom), along with their reverse versions. Severity is graded by how far the septum deflects from the midline. Imaging like CT scans can map the deviation precisely, but many cases are diagnosed with a simple visual exam using a nasal speculum or a thin camera inserted into the nostril.
Treatment Options
If your deviation is mild and symptoms are manageable, non-surgical approaches can help. Saline sprays keep the nasal lining moist and reduce nosebleeds. Corticosteroid nasal sprays reduce swelling in the surrounding tissue, which can open up the airway even though the septum itself hasn’t moved. Antihistamines help if allergies are compounding the problem. External nasal dilator strips can also improve airflow during sleep.
These treatments manage symptoms but don’t correct the structural issue. When symptoms are persistent and disruptive, septoplasty (surgical straightening of the septum) is the standard fix. The procedure repositions or removes portions of cartilage and bone to center the septum. Patient satisfaction ranges widely in long-term studies, from about 50% to 100% depending on the study, with one large assessment finding 88% of patients moderately satisfied or better at one year. It’s effective for many people, but not a guaranteed cure for nasal obstruction, since other factors like tissue swelling or nasal valve collapse can contribute to blockage independently.
For children and teenagers, surgery is typically delayed until after puberty. The septum grows rapidly through the teen years, and operating too early risks impairing normal nasal development. Once growth stabilizes, usually by the late teens, the procedure becomes a safer option.