Last 3 weeks -my throat seems irritated near the back but im only noticing it when i swallow food. im not sick at all. what could be possible causes?

Throat irritation: There are numerous causes of throat irritation, but many of them are more likely to be associated with some kind of illness. Since you aren't really sick, it narrows things down considerably. Allergies could cause throat and you don't have to be sick. Acid reflux can cause irritated throat, too. Usually, there is some heartburn or maybe throat clearing. Tonsil stones can cause this, too.