Many people believe that the moon’s periodic changes affect human beings. The most obvious example is the menstrual period of women. Under normal conditions, a woman’s period occurs every 28 days, exactly in between a sidereal month (the time between maximum elevations of a fixed star as seen from the moon, which is approximately 27 days) and a lunar month (29 days).
According to Shi Yukun, a doctor of Chinese medicine, the moon’s cycle is also related to when human beings are born. Most babies are born just after the full moon.
The phase of the moon plays a role in human beings’ mental states. Ancient Babylonians referred to patients with mental disorders as “lunatics,” which means having diseases that are influenced by the moon. Today, studies have shown that psychopaths have a higher tendency to exhibit mental disorders during the full moon.
The moon also affects a person’s mood. The full moon can cause one to feel anxious, nervous, disturbed, and develop hallucinations. In addition, during the full moon, people have a higher tendency to relive their past memories, making them feel sad and depressed. Many poets composed some of their best work during the full moon.
The ancient Chinese book Common Questions: Theory on Eight Divinities says, “When the crescent emerges, the blood and qi [the energy that constitutes the human body and sustains life] start to strengthen, and the safeguarding qi starts to circulate. With the full moon, the blood and qi are sufficient, and the muscles are strong. When the moon is waning, energy channels weaken, the safeguarding qi leaves, and only the shape remains.” That is to say, the human body's blood, qi, muscles, and the strength of energy channels are related to the moon’s phases.
Seeing these phenomena from a different point of view, one could consider that perhaps the human body is simply universally connected, not because of the moon, as the moon may only be an object that responds accordingly to the rhythm of the universe.