If tendinitis goes for too long without being treated, it can lead to further foot complications that can keep you off your feet for longer. You may think it is not much of an issue and you push through.
This is not the wisest thing to do as it can just make matters worse. If left untreated, tendinitis can become chronic. It can also lead to a weakening of the tendon or a rupture of the same and permanent damage to the affected tissues.