I had a hysterectomy 4yrs ago. i'm lactating again but now its green in the left breast. any idea what it is..... also i had my thyroid removed?

Green discharge: I would suggest getting evaluated by your OBGYN or primary care doctor. Green discharge from the nipple is not normal and needs evaluated. Causes could range from a milk duct infection/mastitis to cancer to a gladular/hormonal issue. A mammogram or breast ultrasound may be necessary depending on what your doc finds on history and physical examination