It has been observed through scientific investigation that stress & general fatigue may lead to recurring aphthous stomatitis (RAS) although scientific studies of linking stress and mouth ulcers are sometimes contradictory.
One issue is certain: recurring aphthous stomatitis can increase stress & anxiety levels which in turn can lead to other stress-related pathologies13
Mouth ulcers have direct consequences (pain, causing difficulties to swallow, talk, etc.) but also potentially indirect consequences.