Breast atypical hyperplasia is not cancerous, but it may develop into breast cancer. Breast atypical hyperplasia mostly occurs in the ducts of the breast and is mainly caused by internal and external stimuli. It belongs to the category of precancerous lesions and has not yet developed into cancer. As long as timely and appropriate treatment is provided according to the doctor’s instructions, most patients can recover; however, if the condition continues to deteriorate and develop without targeted treatment, it may evolve into breast cancer. Breast atypical hyperplasia is generally categorized into mild, moderate and severe, all of which gradually become severe and eventually become intraductal and invasive breast cancer, with the highest prevalence in severe patients. Therefore, patients with atypical breast hyperplasia are advised to go to the hospital for timely consultation and early treatment to avoid deterioration of their condition.