Medical Encyclopedia definition: Stress is a feeling of emotional or physical tension. It can come from any event or thought that makes you feel frustrated, angry, or nervous.
Mayo Clinic article that includes: Stress that's left unchecked can contribute to many health problems, such as high blood pressure, heart disease, obesity and diabetes.
Webmd article that includes: Forty percent of U.S. workers admit to experiencing office stress, and one-quarter say work is the biggest source of stress in their lives.