How would i be able to tell my gynecomastia is based off of hormones and not a kidney tumor?

See an endocrinologi: Kidney rumors are unlikely to cause gynecomastia. Most of gynecomastia patients have normal hormone levels. Some could be related to a particular testicular tumor. An ultrasound of the testicles should be performed to rule it out.

Hormone analysis: Your medical physician can do blood tests to make sure you do not have a tumor causing your breast to grow.