The bathroom is the part of the house where we perform functions that are considered private and "dirty", so a bathroom in a dream can be a place for dealing with "dirty" thoughts that we do not want to reveal to others and, sometimes, even to our conscious selves.
Bathrooms are also places where we clean and groom ourselves so that we can be presentable to the outside world. Therefore, bathroom dreams can often have to do with our feelings about how others perceive us.
Using the Toilet
A dream that you need to urinate or defecate can sometimes be based on a real physical sensation.
You may dream that you need to urinate or make a bowel movement just before you wake up, when you really do need to go to the toilet.
The feeling that you need to urinate in a dream can be caused by sexual stimulation.
Dreams in which you defecate or urinate can also have a psychological cause - relieving yourself of body waste can represent ridding yourself of unhealthy, negative thoughts and emotions.
Because water in dreams is often associated with the emotions, urine can represent negative, unhealthy emotions. Feeling that you desperately need to urinate in a dream can mean that you need to release such emotions.
Defecating in a dream may be associated with the need to rid yourself of a mental or emotional burden that you are carrying in waking life.
Can't Find a Toilet
It is common to dream that you desperately need to urinate or have a bowel movement, but that you can't find a bathroom or a toilet, or that all the bathrooms are occupied, or that all the toilets you find are out of order.
This can mean that you have repressed thoughts that need to come to the surface, but you do not yet know of a way that you can release them safely.
Dreaming that you will have to urinate in front of others can mean that you are afraid of others discovering your darkest secrets.
Bathing or Showering
Bathing or showering in a dream often represents cleansing yourself emotionally or spiritually.
Taking a bath or a shower can symbolize getting rid of old, negative thoughts or habits.
Showering and bathing may be associated with transformation.
Grooming yourself in a bathroom in a dream can represent an attempt to hide the aspects of yourself that you don't like from the outside world.
Looking at yourself in a mirror in a dream may be associated with a need to get a better understanding of who you truly are.
When the mirror is in a bathroom, it may be important for you to face the things about yourself that you think are dirty, and that you like to keep hidden.
Because hair is a symbol of strength, combing or brushing your hair in a dream can symbolize a need to recognize your strengths but, at the same time, to keep them under control.
Using a comb to take the knots out of your hair can symbolize untangling a complicated situation.
Shaving in a dream can symbolize a desire to change something about yourself.
If you dream that you are shaving off a mustache or beard, you could enter a new stage in your life.
Applying makeup in a dream can reflect a need to have others accept you and like you.
You may be afraid that there are aspects of yourself that you need to hide from other people.
Putting on makeup can be a sign that you are being deceptive about something in waking life.