Breast cancer is the most common oncological disease in women. Consequently, in all developed countries preventive breast check-up programmes are carried out. Breast examinations are obligatory for all women from the age of 40 even when they have no complaints and feel no changes. This age threshold was not selected by accident. The majority of those with breast cancer are older than 45. Three to five years pass while the tumour develops from a single cell to 1 cm and becomes palpable. Women whose relatives – mother, grandmother or sister – had breast cancer should be particularly cautious. For them, mammography examinations should start a few years earlier. Furthermore, mammography is compulsory before starting replacement hormone therapy. Mammography imaging is read by doctors with extensive experience in breast disease diagnostics.