My memography for both the breast says that both the breasts show dense heterogenous fibroglandular stroma. there is no other parenchymal lesion.

Mammograms: Breast "architecture" is very varied. Some breasts are very dense with breast fibrinous stroma, others are more "fatty" however, there is a wide range of normal, and what you describe is a normal breast architecture. Usually, there is fatty replacement as you age. You have nothing to worry about.

Mammography: Mammograms are great screening tools. Dense breast tissue is not cancerous. Your mammogram should come with a birads reading telling the likelihood of cancer vs not cancer. This should also give you an idea of follow up- by exam or further studies. Your mammogram sounds normal but should be followed up by your ordering physician. It can only be truly interpreted by an accompanying exam.