extra caffeine can cause gastric discomfort the pain of which can be felt at one side of breast mostly left side but right also is possible and some times whole chest. get evaluated for any local pathology like mastitis. i hope it helps. stay in touch with your healthcare provider for further guidance as our answers are just for education and counselling purposes and cannot be an alternative to actual visit to a doctor. take care khan
could extra caffeine consumption be a cause of mild unilateral breast tenderness?