The meaning of dream regarding crying usually has something to do with self imposed emotional repression. This could also be due to repression from an external source, such as a person that will not allow you to cry or a person that you are afraid to cry in front of. But for the most part, a dream dictionary will tell you that crying means that you need to express your emotions better in life. If you are unable to express emotions that are really important in life, then these emotions might show up in your dreams since it is the only place you can find true release. While it may feel good to cry in your dreams, crying is a negative dream symbol in terms of what it means about your everyday life.
When you cry in real life, it is usually done because you are emotionally overwhelmed. Something very powerful has occurred recently, and you want to put it all behind you, but you need to get your feelings off your chest first. The dream meaning is consistent with this idea, that you have some emotions that you feel the need to express. However, if you find yourself doing this in your dreams instead of your waking life, it could mean that you are poorly managing your own emotions.
Even if a dream involves someone else crying, most dream meanings agree that this is a simple case of projection. Your feelings are so woefully repressed that it becomes easier for you to deal with your emotions indirectly rather than directly. It is easier for you to handle it when you see someone else crying than if you see yourself crying in a dream. If you wake up out of a dream crying, then this is usually suggestive of another kind of repressed emotional hurt. You need to stop lying to yourself and to others and really deal with the subject of your sadness head on. This is what most dream interpretations agree on.
Another dream interpretation regarding crying is when you cry, but no one hears your cries. This is suggestive of feelings of helplessness. When you are feeling totally helpless in life, or feel that nobody is responding to you seriously or taking you seriously, then you may have dreams that nobody is responding to your cries.
When you wake up crying, this is similarly suggestive of negative things involving repression of negative emotions. If dreams are the only place that you can truly find a place to let loose your emotions, then you are truly having issues in life which are preventing you from expressing yourself. Sometimes dreams involving crying can be written off as flukes, but when this type of dream causes you to physically cry while you are awake, then this is one of the few dream symbols that acts as a clear sign that you need to make some lifestyle changes in order to achieve harmony again.