['Chest Pain. Chest pain could be caused by a number of different factors ranging from muscle soreness to a heart attack. ... ', 'Abdominal Pain. ... ', 'Sudden Weight Loss or Gain. ... ', 'Changes in Appetite. ... ', 'Fatigue or Weakness. ... ', 'Shortness of Breath. ... ', 'Nausea or Vomiting. ... ', 'Difficulty Swallowing.']