Pain is typically defined by neuroscientists as an unpleasant sensory and emotional experience associated with actual or potential tissue damage (Sufka & Lynch, 2000).  Pain is highly associated psychologically with distress as an undifferentiated protest against anything that is unpleasant or aversive (Kalat & Shiota, 2007).  The function of pain is generally believed  to be the escape and avoidance to prevent further trauma and/or promote the healing processes (Williams, 2002).  Pain is experienced by everyone, but is expressed in different ways (Llewellyn, n.d.).  These definitions suggest pain is an emotional experience.  I will show how pain fits into all five criteria of a basic emotion, then I will compare pain to the emotions already classified as basic in the way they are related to mental illness in order to provide further evidence that pain is in fact a basic emotion.