Lynetta
Many restruants will put a food preservative in their salads. This preservative often will contain MSG. The symptoms you are having could be caused by an allergic reaction to MSG. Many people have reactions ranging from what you are describing to Migraine headaches after eating anything containing MSG. Chinese food traditionaly contains this ingredient. Because so many people have reactions to MSG, there has been a movement in recent years to eleminate this. Also, many restruants and Chinese places will advertise being MSG free. Be aware this is also found in some wines and food enhancers such as Accent. Good Luck