The main causes of painful hard lumps in the chest of 17-year-old patients include the following aspects: 1. The nucleus of the breast, which is not fully developed, is a normal physiological state, and patients are advised not to touch it arbitrarily; if they are not sure, they can go to the hospital for ultrasound to determine that the painful hard lumps will subside naturally while waiting for the breast to continue to develop. 2. It is important to note that the more common cause of breast pain in women is breast enlargement, but it rarely occurs in 17-year-old women.