Physical stressor is result from internal physical symptoms like headaches, stomach problems, heat, cold, excessive noise as well as lack of rest and sleep. Physical stressor can also be arising from time pressures or the unrealistic expectations we place on ourselves. Read more on www.texmed.org/template.aspx?id=4983.
Yes, you are correct. It can also be in arms, legs, etc. Physical stressors or Body Syndromes usually start with feelings or emotions. It would be helpful to know where the physical part of body is "stressed" to find the cause. Daily nutrition intake will take part in this too.