Generally speaking, it is recommended to be over 25 years old. No, some people develop early. If they have symptoms at the age of 20, they can also be tested. According to the routine physical examination, they are all over 25 years old. It is recommended to go to the outpatient clinic for the most basic palpation every one to two years. If necessary, a B-ultrasound is enough. If you are a woman over the age of 35 to 40, it is generally recommended to have regular breast examinations every year, and you must go to a professional physical examination center for at least one palpation and breast B-ultrasound. If you are over 40 years old, you should do it once a year, plus a molybdenum target examination. Many people don't think it's necessary, but people over 40 should have a checkup at least once or twice a year.