Better understanding of tears and why we need to release them is found here.
When I read this post, I realized that I do feel better after shedding some tears. No matter what prompted me to cry, it was necessary to release all of the toxins that have built up over time. It is a gentle cleansing. Maybe that is why we cry when we remember those who have passed on. We still need to release the pain and loss we have inside. By way of the tears, we cleanse these negative feelings out, so we may live anew with love and happiness inside.