(HealthDay News) -- Thyroiditis is an inflammation of the thyroid gland in the neck, located below the Adam's apple and above the collarbone. The thyroid regulates your body's metabolic processes, controlling your heart rate, for example.

The American Academy of Family Physicians says thyroiditis often is the result of an autoimmune disease, an attack on the body by its own immune system. An infection or certain drugs also can lead to thyroiditis.

Depending on its characteristics, thyroiditis symptoms can mimic those of an underactive or overactive thyroid. These symptoms may include:

• Unexplained weight loss or gain.
• Muscle aches or weakness.
• Depression, nervousness or anxiety.
• Fatigue or difficulty sleeping.
• Rapid heart rate.