We usually express the feeling of sadness in tears or screaming even anger at some point... Something unexplainable. It bursts out in a physical pain called tears or even goes as far as blocking your complete breathing system from your nose till your lungs. You can hardly swallow and you loose your appetite and your energy. It is super intense, but by being sad it will be accepted or hushed. But it won't be buried completely...
The Disney & Pixar movie Inside Out (2015) explained it perfectly. You can't always be happy. Being sad is a good thing, apart from being angry, have fear and feel disgusted. It helps you deal with certain memories and emotions, where you can't get out from.
I hate the unstoppable crying. The symptoms of not being able to breath without having tissues to safe you from drowning... The puffy eyes the next morning... Worst of all is, is the three days scaly nose and three days of headache! Usually I have that during a terrible cold or when I have a fever like most of us. My brain and my emotions stopped working properly. I had to sleep almost an entire day?! Yes, that was the entire purpose of vacation being able to sleep. A controlled sleep, three days of just an entire days sleep, so actually 8 hours per day...? I woke up every three or two hours, so how well is that going? I was and might still be mentally worn out.
But I guess... I am still recovering or dealing with all the sadness in my life... I will be fine as long as my chronic headache won't disturb me.