Yes, thyroid disease can affect your mood — primarily causing either anxiety or depression. Generally, the more severe the thyroid disease, the more severe the mood changes.

If you have an overactive thyroid (hyperthyroidism), you may experience:

• Unusual nervousness
• Restlessness
• Anxiety
• Irritability

On the opposite end of the spectrum, if you have an underactive thyroid (hypothyroidism), you may experience:

• Mild to severe fatigue
• Depression

Still, it's unlikely that emotional symptoms such as anxiety or depression would be the only evidence of thyroid disease. Thyroid disease is usually associated with signs and symptoms such as:

• Weight gain or loss
• Increased sensitivity to hot or cold temperatures
• Bowel movement changes
• Menstrual irregularities

Appropriate treatment — such as medication that blocks your body's ability to produce new thyroid hormone or replaces missing thyroid hormone — usually improves both emotional and physical symptoms caused by thyroid disease.