A deviated septum can be genetic, but most cases result from a mix of inherited facial structure, pressures during fetal development, and physical trauma at birth or later in life. About 80% of people have some degree of septal deviation, according to Stanford Medicine, which means a perfectly straight septum is actually the exception. Genetics plays a real but partial role in determining whether yours is one of them.
The Evidence for Hereditary Septal Deviation
At least one specific type of septal deformity appears to run strongly in families. A study published in the International Journal of Pediatric Otorhinolaryngology examined 779 children and found that among the 22 children with a particular deformity pattern (classified as type 6), both parents carried the same deformity in 21 of those cases. None of the 48 parents of children with straight septums had this deformity. That correlation was statistically significant (P<0.001), which is about as clear a signal as you get in genetics research.
This type of deviation is linked to developmental disturbances in the upper jaw complex, suggesting the genes involved influence how the entire midface grows, not just the septum itself. Researchers have noted that identifying the specific chromosome responsible could eventually allow early intervention, though that remains a long way off. The broader takeaway is straightforward: if both your parents have a deviated septum, you’re more likely to have one too.
How the Septum Forms Before Birth
The nasal septum begins forming around the sixth week of embryonic development. Contrary to older medical thinking, it doesn’t grow downward from the roof of the nasal cavity like a curtain. Instead, it develops from tissue between the earliest nasal passages and expands from front to back, eventually fusing with the palate as the roof of the mouth shifts into its horizontal position. This is a complex process with multiple moving parts, and small disruptions at any stage can produce a crooked result.
Because the septum develops alongside the palate and jaw, anything that affects midface growth can influence septal alignment. This is why genetic connective tissue disorders like Marfan syndrome and Ehlers-Danlos syndrome are associated with deviated septums. These conditions alter the structural proteins that form cartilage and bone throughout the body, including the nose. If you have one of these conditions, septal deviation is more likely to be part of the picture.
What Happens During Birth
Even without a genetic predisposition, the birth process itself frequently shifts the septum. Roughly 58% of all newborns show some degree of septal deviation, with about 4% also having a visible external nasal deformity. That’s a remarkably high number, and it points to the physical forces involved in delivery.
During vaginal birth, the baby’s head rotates through the birth canal, and the pressure from the canal walls pushes on the soft cartilage of the nose. The direction of the deviation depends on the baby’s position. Babies in a left-facing position tend to develop rightward deviations, while babies facing right tend to deviate left. This happens because the head’s rotation presses the cartilage out of its groove in one direction. Babies delivered by cesarean section have lower rates of anterior septal deviation, which confirms that birth canal pressure is a significant factor.
There’s also an evolutionary theory: as human skulls have evolved to accommodate larger brains relative to the face, the bony framework of the nose has reduced in size faster than the flexible cartilage inside it. The septum, in other words, may be slightly too large for the space it occupies in many people, making it inherently prone to buckling.
Genetics vs. Injury Later in Life
Trauma is the other major cause, and it’s the one most people think of first. A broken nose from sports, a car accident, or even a childhood fall can shift the septum permanently. These acquired deviations are distinct from congenital ones, though the practical effect on breathing is the same.
Distinguishing a genetic deviation from a traumatic one isn’t always simple. An ENT evaluates the nose with a direct visual exam, sometimes using a thin camera (nasal endoscopy) or a CT scan, looking at the pattern and location of the bend. Congenital deviations often involve the deeper cartilage and bone structures that formed during development, while traumatic deviations tend to affect the front of the septum and may show signs of old fracture. But in practice, many adults have some combination of both: a mildly deviated septum from birth that worsened after an injury years later.
What This Means for Your Family
If you’re wondering whether your deviated septum came from your parents, the honest answer is: possibly, especially if they have one too. The strongest evidence for direct inheritance involves specific deformity patterns tied to midface development. For the broader population, genetics sets the stage by determining the size and shape of your nasal structures, your cartilage flexibility, and how your midface grows during childhood. Whether that translates into a meaningful deviation depends on additional factors like birth mechanics, facial injuries, and simple anatomical luck.
A deviated septum is not something you can prevent through lifestyle choices. If both parents have noticeable deviations, it’s reasonable to expect their children may as well, but many of those deviations will be mild and never cause symptoms. The 80% prevalence figure is a reminder that most people live with some asymmetry without ever knowing it. Severity matters far more than the deviation itself, and severity is shaped by the full combination of genetics, development, and life experience.