Breast nodule 4mm*5mm*4mm refers to the size of the breast nodule, and upright refers to the long perpendicular to the chest. The cause of breast nodule is still unclear, and it is found that it may be related to emotional factors, endocrine level disorders, and medication factors. 1. Emotional factors: Emotional factors may also cause breast nodules, such as depression, anxiety, anger, excessive stress, etc. can cause endocrine level disorders, forming breast nodules. 2. Endocrine disorders: Patients with endocrine disorders may also cause breast nodules, for example, elevated levels of estrogen will stimulate breast tissue, resulting in nodules. 3. Drugs: If patients use a lot of health products containing hormones for a long period of time, it may also cause stimulation to the breast gland, resulting in breast nodules. It is recommended that patients suffering from breast nodules should consult a doctor in time to clarify the pathological nature of the nodules and standardize the treatment under the doctor’s guidance to avoid delaying the condition.