The hypothesis of this study is that biological markers are present in the body that are good indicators of chronic pain. Eligible participants will be assessed at baseline and after receiving a series of acupuncture or "sham" acupuncture (something that resembles, but is not, active acupuncture) sessions. If the subject qualifies for the investigators' research and are subsequently enrolled in this study, they will be randomly assigned (like the flip of a coin) to one of these two groups. Acupuncture, as previously shown by this group, leads to improvements in both clinical and evoked pain associated with fibromyalgia. The study involves two magnetic resonance imaging (MRI) brain scans, one at the beginning and one at the end of the study. Another optional portion of the study would involve 2 PET (positron emission tomography) scans of the subject's brain, one at the beginning and one at the end of the study; this type of scan allows us to get more specific information about the subject's brain function during an acupuncture session.

Inclusion Criteria:

Inclusion Criteria for Fibromyalgia Volunteers:

• Has met American College of Rheumatology (1990) criteria for the diagnosis of fibromyalgia for at least 1 year
• Chronic pain more than 50% of days
• Willing to limit introduction of any new medications or treatments for fibromyalgia during the study
• Able to attend study visits up to three times weekly
• Right-handed
• Be capable of giving written informed consent

Inclusion Criteria for Healthy Volunteers:

• Willing to refrain from alcohol intake for 48 hours prior to brain scans
• Be right handed
• Be capable of giving written informed consent

PET Inclusion Criteria:

• Willing to refrain from alcohol intake 48 hours prior to brain scans
• Capable of giving written consent

Exclusion Criteria:

Exclusion Criteria for Fibromyalgia Volunteers:

• Knowledge that could prevent "blinding" of the participant to the study interventions (including previous acupuncture treatment)
• Presence of a known coagulation abnormality, thrombocytopenia, or bleeding diathesis that may preclude the safe use of acupuncture
• Autoimmune or inflammatory disease (in addition to fibromyalgia) that causes pain (e.g., rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel disease)
• Daily use of narcotic pain-relievers
• History of substance abuse
• Simultaneous participation in other therapeutic trials
• Pregnant or breastfeeding
• Current severe psychiatric illness (e.g., schizophrenia, major depression with suicidal ideation)
• Condition that may make exposure to fMRI medically inadvisable
• Any condition that may prevent satisfactory completion of the study protocol

Exclusion for Healthy Volunteers:

• Autoimmune or inflammatory disease (in addition to fibromyalgia) that causes pain (e.g., rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel disease)
• Having met the ACR criteria for FM
• Simultaneous participation in other therapeutic trials
• Pregnant or breastfeeding
• Current severe psychiatric illness (e.g., schizophrenia, major depression with suicidal ideation)
• Condition that may make exposure to fMRI medically inadvisable
• Any condition that may prevent satisfactory completion of the study protocol

PET Exclusion Criteria:

• Meets any of the fMRI exclusion criteria
• Current major depression
• Condition that may make exposure to PET medically inadvisable