Hi Rae,
According to your other post you are 16 and took a bottle of Flexeril. You wrote, "I am 16 and i have depression and i tried to overdose on Flexeril."
http://www.medhelp.org/posts/Pain-Management/How-long-dose-it-take-to-detox-from-Flexeril/show/2621705#post_12760718
You are showing those signs of depression my dear. You may not consciously "feel sad" at the moment of tears but your body is feeling an emotion and is expressing it.
Anxiety or Depression can make you cry "for no reason". However there is a reason. Your body is doing it's best to release the emotions/anxiety/depression that you are feeling internally. Depression can often have an effect on your ability to control your emotions, any emotion. Crying is a natural stress reliever. When you cry, you're letting out emotions. Your body designed crying specifically to provide this level of stress relief. In a nutshell, your body is actually trying to help you.
Being a teenager is difficult on it's own, add depression and anxiety and it can be more than difficult. Please sweet soul seek out an adult to help you through this time. A guidance counselor, clergy, trusted adult relative or a medical provider can assist you.
You were offered some good suggestions on your previous post. I urge you to please select a suggestion that is doable for you and go with it. I don't know your situation but I do know there are kind caring ppl in this world willing and able to help you make your life better.
You asked if this is something that can hurt you later on in life - the answer is yes - depression or what ever it is that you are experiencing requires early treatment. The sooner the better.
I'll be watching for your updates.
Take Care,
~Tuck