Complex sentence: Pain is a sensory and emotional experience, and a part of the emotional element is suffering, a subjective phenomenon associated with such experiences as pain, hunger, fatigue, nausea, loneliness and despair.
Split into simpler sentences: Pain is a sensory and emotional experience, and a part of the emotional element is suffering. Suffering is a subjective phenomenon associated with such experiences as pain, hunger, fatigue, nausea, loneliness and despair.