I have the lower sanpaku show, noticed after I read about it.

On days where I'm tired I can get a very large show beneath my eyes.

Makes sense to me actually. If someone is tired, they are less aware of their surroundings and less capable of reacting to their environment or it is trying to get them any ways. Either way, they are more likely to die.

For the upper show, it makes sense that it reflect a different psychological phenomenon. While the bottom shows external stress and tiredness, the upper show indicates mental instability.