Typical hyperthyroidism is relatively easy to diagnose. However, 20% of patients have atypical symptoms, so we need to pay attention to identify these “masked” hyperthyroidism. Clinical measurements of iodine uptake, serum T3 and T4 measurements, and imaging tests can help to clarify the diagnosis. Nearly 10% of patients with hyperthyroidism have heart-like symptoms, such as arrhythmia, atrial fibrillation, heart enlargement, and in severe cases, heart failure. It is easy to be misdiagnosed as myocarditis, rheumatic heart disease, etc. Diarrhea: Some patients with hyperthyroidism have diarrhea as their main symptom, with several times more stools that are thin or watery. The reason for this is that some hyperthyroid patients have increased bowel movements due to thyroid hormones. It is often simply thought of as chronic bacillary dysentery, colitis, or gastroenteritis, and is more common in young and middle-aged patients. Easily confused with psychoneurological diseases: Due to excessive secretion of thyroxine, some patients with hyperthyroidism have increased excitability of the central nervous system, manifesting as hypersensitivity, talkativeness, agitation, irritability, insomnia, and eccentricity, etc. Some patients also have psychotic-like symptoms such as melancholy and mania, which can easily be thought of as neurosis, bipolar disorder, menopausal syndrome, etc. Most patients with hyperthyroidism have symptoms of proptosis of varying severity, either bilateral symmetry or one side is more prominent. In particular, in malignant proptosis, the patient’s eyes protrude, combined with membrane ectropion, congestion and edema, tearing and photophobia. If the doctor is blinded, he or she may misdiagnose the hyperthyroidism as keratitis or posterior orbital tumor as a matter of course. Fever is often associated with hyperthyroidism. Some patients have low fever, with body temperature between 37.5℃ and 38℃, accompanied by palpitations and rapid heart rate, and other discomforts, which can be easily diagnosed as rheumatic fever, tuberculosis, urinary tract infection, etc. etc. We should be highly alert to the above-mentioned forms of hyperthyroidism and pay attention to the routine thyroid-related examinations when these symptoms appear.