You are absolutely correct when you say that adenoids can affect breathing in childhood. Adenoids are lymphoid tissue in the back of your nose (nasopharynx) that is part of something called waldeyer's ring. They are similar to the "tonsils" in the back of your mouth. In childhood, lymphoid tissue can hypertrophy significantly to the point that the tonsils can obstruct breathing when sleeping (and can cause sleep apnea
), and the adenoids can completely block the back of the nose. In some kids this requires surgical removal. However in adulthood the lymphoid hyperplasia tends to "burn out" and the adenoids and tonsils generally shrink down. It is very rare for adenoids to actually cause any kind of obstruction in adults. In fact generally if there is any kind of adenoid hyperplasia seen, it is because the person is a smoker, and the adenoids are irritated and swell from smoke irritation. There are many other different causes of nasal obstruction. I recommend that you make an appointment with an ENT (Ears Nose Throat) physician to get evaluated. They will be able to examine your nose, and help determine the cause of your nasal obstruction.