Like mammo said this happens to a lot of people...We have days that it just kinda hits us and I don't think you have anything to worry about unless in becomes more frequent.
Some times when i have my bad days at night or even on my breaks at work...I will do guide relaxation...if you have an ipod you can download podcast from itunes that are free...this is also great if you are having trouble sleeping...
Hi Jackie. Yes, this has happened to a lot of us, and it is often a sign of depression. Feeling sad, hopeless, down, crying, are only a few of the symptoms, but you are not alone. There are so many wonderful people on here to listen and help. If this is interfering with your daily life, I would seek the help of your doctor to see if you need some therapy, or medication. But we all have "blue days", this is normal, it's when it's happening more often than not, that it becomes a problem. Evaluate what is going on in your life and see if something is making you sad, or does it just happen? Maybe just talking will help you. I hope this helps, and I'm sure others will respond to your post with lots of support for you.