Why am i always sad or upset for no reason? is this worrying?

You may be depressed: Constant worry is generally unhealthy and falls into the category of "anxiety disorders." however, feeling sad, upset, or irritable "for no reason" sounds more like a clinical depression. Anxiety and depression often coexist. The good news is that they are both treatable. I highly recommend you seek the help of a trained therapist who can help you overcome these uncomfortable feelings.