This is a dream I had when I was in the lower grades of elementary school. "In my dream, I needed to urinate, so I went outside my room and found the compost pile behind our house. I relieved myself there to my heart's content. It felt so refreshing." When I woke up, the area below my waist was wet. I had drawn a map on my blanket. Though embarrassed, when I told my mother I had wet the bed, she laughed heartily and put a sieve on my head, telling me to go get some salt from the grandmother next door. I went to the grandmother and said, "My mom told me to get some salt," and she smiled and went into the kitchen. A moment later, she turned me around, sprinkled salt on the sieve I was wearing, and hit it with a stick while shouting loudly, "How dare you wet the bed!" I ran away in embarrassment. From that day on, I never drew another "map" on my bedding. This dream was created when my full bladder created physiological pressure that stimulated my brain.
Recently, I had another physiological dream. "In my dream, I suddenly needed to urinate and looked for a bathroom, but there was a long line of people and I couldn't relieve myself. I saw a shower room nearby and thought I could take care of business while showering. But when I turned on the shower, no water came out. I woke up feeling frustrated." Upon waking, I felt severe pressure in my bladder. I got up and used the bathroom. As an adult, because I've been toilet trained to endure pressure, the same bladder pressure from childhood manifested as a different type of dream. Pain from bladder distension and the urge to urinate are primarily transmitted to the brain through the pelvic splanchnic nerves. As is well known, for comfortable sleep and good health, it's advisable to avoid drinking water or beverages at least two hours before bedtime. For reference, I call dreams induced by such physical stimuli "physiological dreams."
Alfred Maury conducted experiments on physiological dreams induced by physical stimulation. In his 1861 book "Le sommeil et les rêves" (Sleep and Dreams), he introduced several cases. He asked his servant to apply various stimuli while he slept and recorded his dreams. When the servant held perfume near his nose while sleeping, the following dream was produced: "I was in a famous perfume shop in Cairo. Then I embarked on a wild romantic adventure that was beyond words." Maury's stimulus-induced dream experiments were groundbreaking for their time.
Such physiological dreams from external stimuli can also occur through the consumption of alcohol or chemical substances, and dreams can also be created by internal bodily stimuli.
A woman participating in a dream interpretation group once dreamed of a purse containing rotten meat. Feeling extreme anxiety after this dream, she got a cervical cancer screening. The result was negative. However, she insisted on additional testing. As a result, it was discovered that she had a very aggressive form of uterine cancer. Had it not been discovered in time, she would have lost her life. At the time of the dream, she had no symptoms and was about to leave on a planned trip. She believes she owes her life to the interpretation of the dream group with whom she shared this dream.
Interpreting this woman's dream, it appears the brain (particularly the right brain and limbic system) converted this unpleasant and dangerous bodily signal into a "metaphorically visualized image" rather than "language." The rotten meat symbolizes necrotic body tissue, while the purse symbolizes the woman's uterus. Also, from an information transmission perspective, the vagus nerve connects the brain to the body's internal organs. While awake, external visual and auditory information is so strong that subtle signals transmitted to the brain can be buried. However, during sleep, external stimuli are blocked, and interoception—the brain's ability to focus more on subtle signals from internal organs—develops, allowing us to glimpse bodily abnormalities. Ultimately, I believe the abnormal situation inside the body was transmitted to the brain through the neural pathways of the vagus nerve and pelvic splanchnic nerves, and this stimulus was visualized as dream imagery. This phenomenon where early disease signals appear in dreams is medically called "prodromal dreams."
When you have such unpleasant dreams, it's advisable to first determine whether it's a psychological dream or a physiological dream and respond accordingly. Ultimately, depending on how dreamers interpret and utilize their dreams, they can enhance the breadth and quality of their lives and even prevent misfortune.