Whats the cause of breast fibroids? and when to remove them? assuming the fibroids are all under 1cm and not causing symptoms?

If you know it is a fibroadenoma/fibroid, there is no need to remove it. It is usually that a lump is felt and it is not clear as to the nature of the lump. To be on the safe side the lump is removed and submitted to a pathologist for definitive diagnosis. for info: https://www.cancer.org/cancer/breast-cancer/non-cancerous-breast-conditions/fibroadenomas-of-the-breast.html