Loneliness can cause death. For example: If you have no friends or if you lose them you feel pain. I had this once and I felt extremely lonely. My sudden solitude caused problems with my health. I had strong headaches, my stomach hurt, I had problems to breathe and all that. Some people couldn't take that. They couldn't endure the feeling of loss or loneliness so they would decide to end their life and commit suicide. It's also known that you can literally die from a broken heart (as far as I know). There's a disease called "Broken Heart Syndrome" which causes the heart to not work properly anymore which can lead to your death. In most of the cases it heals but sometimes it's deadly.
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not seeing is a flower