Subacute thyroiditis is commonly referred to, and it is frequently seen clinically with symptoms such as fever, pain in the neck, and mild hyperthyroidism symptoms in the early stages, such as palpitations, insomnia, weight loss, irritability, and increased frequency of bowel movements. Therefore, if you have these symptoms, it is important to promptly visit an endocrinology specialist to see if you are suffering from subacute thyroiditis. Diagnosis can be confirmed through blood tests, thyroid function tests, thyroid ultrasound, routine blood tests, and erythrocyte sedimentation rate tests.