To dream of a penis represents power, virility, and competence. You or some aspect of your personality feels capable or powerful.
To dream of a small represents emotional impotence or powerlessness. You feel totally ineffective in some area of your life. Feeling weaker or less important than other people.
To dream of a large penis represents you or some aspect of your personality that is very powerful, capable, or competent. Positively, it may be a sign that you feel in control successful, or more powerful than others. Feeling that you are clearly a bigger winner than other people. Negatively, it may reflect problems or other people who hold greater power than you do. A problem or competing aspect of your life that is too powerful for you.
To dream of losing your penis represents feelings of losing power or being stripped of power. A tragic loss of power. Feeling stupid for trying to boss people or trying to make anyone else listen to you. Feeling that power or a leading role has been taken from you. An assertive role that feels is impossible to maintain. Feeling like a big weak loser. Feeling forced to be nice to people who don't ever need to be nice to you. Jealousy of your impotence.
To dream of your penis bleeding represents a weakening sense of power, capability, or competence. Your abilities, leverage, or strengths may feel like they are slowly being lost. Losing respect, pride, or feeling embarrassed.
If a woman dreams of having a penis it may reflect waking life situations where she is asserting herself, making powerful decisions, or showing others that she is not easy to push around.
For women and gay men to see a penis in a dream it may reflect sexually desirous thoughts or your desire to have something you like happen.
Dreams related to penis size are common to men having issues with insecurity related to the size of their penis.
Example: A man dreamed of having surgery done to his penis that he felt was dangerous. In waking life he had serious insecurity problems with women and was about to have a consultation with a psychiatrist to help him with his problem.
Example 2: A woman dreamed of seeing men with long penises while another man held her down and tortured her. In waking life she felt that she was being unfairly picked on by "cooler" more stylish people than her. The men with long penises may have reflected her feelings about people making fun of her being undeniably more of a winner than her because of their better fashion style.
Example 3: A girl dreamed of thinking that a boy she had a crush on had a small penis. In waking life she felt that the boy she had a crush on was too shy to spend time alone with her.