When the dreamer cries in his dream, then such dream shows the unfavorable feelings the one is suffering. Perhaps the dream balances the state of your mind, where you feel stressed and frustrated in your waking life, but you are unable to express those emotions. In the dream the unconscious mind of yours gives you the release and lets to get rid of those emotions. In our waking life we are willing to repress and ignore our emotions. If you saw the other person crying in a dream, then such dream could reflect your own feelings. Perhaps you are the person who almost never cries, therefore the action of crying is forwarded to another person. If you woke up and been crying in your waking life, then such dream indicates the very hard feelings you were hiding and now you are releasing it. The dream could also indicate the fear of losing someone you love. If no one helped you in a dream, while you were crying, then it shows how powerless and incapable you are feeling. The dream about crying suggests you to acknowledge yourself and believe in yourself, as it is ok to cry from time to time.
Read more about dreaming of Cry in other dream meanings interpretations.