What Are the Symptoms of High Thyroid Levels?

By Staff WriterLast Updated Apr 13, 2020 3:34:05 PM ET
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Symptoms of overactive thyroid, or hyperthyroidism, include double vision, bulging eyes, hair loss, heart arrhythmia, goiter, muscle weakness and rapid heartbeat, states WebMD. These symptoms are often unclear and can also resemble those of other conditions or illnesses.