What are some physical signs of stress?

'fight or flight': Stress causes increased activity in the sympathetic nervous system and the release of stress hormones. As a result: heart rate, blood pressure, and breathing rate increases; there is increased sweating; skin temperature decreases as blood shifts to the vital organs; there can be muscle tension or tremors; GI disturbance such as nausea, stomach ache, or diarrhea; pacing, hand-wringing, etc.