One nostril consistently moves inward more than the other when I breathe in. Could this be a deviated septum?

Thanks for your question. This is a problem I see with many patients, and there may be several reasons why this is occurring. The side of your nose that is moving inward may be narrower than the other side, and a deviated septum can certainly contribute to the narrowing. This narrowing is more likely to cause the collapse that you are observing. Another reason could be from inherent structural weakness of the cartilage on that side of the nose. However, the cumulative effect that you are describing is something called nasal valve collapse. There are specific maneuvers that can be performed during nasal surgery to correct this problem. I would advise an in-person consultation so a proper exam can be conducted. This will be helpful to look at the other side of the nose, too. Make sure you consult with an experienced, board-certified, facial plastic or plastic surgeon who has experience addressing both the cosmetic and functional aspects of the nose.

You may have some structural weakness in your nostril. Your nostril is meant to remain open while you breathe in to allow air to flow. You could either have a weak Internal Valve or a collapsing alar rim. While a Deviated Septum does not cause the nostril to move inwards, it can block the passage and compounding your breathing difficulty. Surgery can help by supporting the weak nostril with a cartilage graft taken from your nasal septum while you undergo a Rhinoplasty. 

 When one nostril collapses inward with breathing,  it is usually result of valve collapse or alar rim collapse. Both of these are treated with cartilage grafting techniques. Cartilage grafts are harvested from inside of the septum of the nose, fashioned and placed along the tip of the nose to give structural support to prevent collapse. For more information and many examples, please see the link and the video below

There could be several factors contributing to your nasal obstruction. A deviated septum is certainly a possibility. This can be due to previous trauma to the nose or something that you were born with. Additionally, if a nostril is lacking support, this can cause it to collapse when breathing inward(as this creates negative pressure) and leads to an obstruction on that side. I would recommend seeking a consultation with either an ear, nose, and throat surgeon or a rhinoplasty specialist so that you can be thoroughly evaluated. 

It sounds like you may have either internal or external nasal valve collapse. This means that the cartilage structure of your nose is not standing up to the pressure of the flowing air. This can be accentuated by a deviated septum or can have no relation to the septum. It is important to see someone in person who can examine the inside of your nose and help make the appropriate determination. Best of luck