Depression can cause physical symptoms. Signs of depression can include feeling sad, hopeless, worthless, or guilty, loss of interest in activities that previously gave you joy, fatigue, problems concentrating, problems sleeping, either too much or too little, appetite loss or weight gain, irritability, and suicidal thoughts. Symptims also include headaches, muscle aches, and digestive problems.
If you are feeling the emotional effects of depression is addition to the physical problems, your symptoms are probably related to depression. You should discuss this with your doctor so you can get treatment.
Shingles does not usually cause prolonged joint pain, upset stomach, and headache like you describe. However, depression can suppress your immune system and make you more prone to infections like shingles.
Here is a website on depression:
http://www.nimh.nih.gov/publicat/depression.cfm#ptdep3
Here is one on shingles:
http://www.ninds.nih.gov/disorders/shingles/shingles.htm
I hope this answered your questions. If not please let me know.
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