The “sunset phenomenon” of anxiety disorders refers to the fact that some people with anxiety disorders experience increased anxiety or anxiety-induced physical symptoms around sunset, i.e., dusk. Anxiety-induced physical symptoms refer to internal anxiety expressed through physical symptoms, which can appear in any part of the body from inside to outside, from head to toe, such as headache and dizziness, tinnitus and ringing in the ears, neck and shoulder pain and discomfort, foreign body sensation in the throat, chest tightness and shortness of breath, palpitations and panic, back pain, abdominal distension and stomach pain, gas and pressure, frequent and painful urination and bowel movements, limb weakness, itchy and tingling skin, and insect crawling sensation. Of course, not all patients with anxiety disorders have this “sunset phenomenon”, and there are some patients who have the opposite, being heavy in the morning and light in the evening. However, “early onset and late onset” is more often seen in endogenous depression, but not necessarily in bipolar depression, which is often accompanied by anxiety, as suggested in the article: Many “intractable depressions” are actually anxiety disorders. Why do people with anxiety disorders experience sunsetting? Although this phenomenon is still relatively common in people with anxiety disorders and causes problems for many patients, no one has looked into its causes. I presume that there may be several reasons. 1. It may be caused by periodic changes in the body’s biological clock, endocrine hormones and neurotransmitter concentrations, such as a decrease in the brain’s 5hydroxytryptamine concentration in the evening, and most of the drugs currently used in clinical treatment of anxiety disorders increase the 5hydroxytryptophan press. 2, the lack of security is one of the main reasons for the formation of anxiety disorders, and light will have an impact on people’s sense of security. When the light is dark, people can’t perceive their surroundings sharply, people’s sense of security will be reduced, and thus there is an increase in anxiety. Most people are not afraid of ghosts during the day, but are more or less afraid once the night comes, for the same reason. Some people experience increased anxiety and feelings of victimization in the shower because the water, especially shampoo, obscures their vision, and the sound of the water interferes with their sense of hearing. Children lack the strength to protect themselves, so many young children cry and become restless in the evening, which is also a sign of anxiety. Note: The lack of inner security in people with anxiety usually comes from family factors in childhood, such as neglect, abandonment, abuse, isolation, overprotection, serious illness in the family, poor parental relationship, and lack of parental tolerance. Experiencing serious adverse events in subsequent school, work and life can also have an impact on a person’s sense of security. 3. Another important reason for the formation of anxiety disorders is people’s internal fear of death. A significant proportion of anxiety disorder patients become ill when a loved one, close friend or colleague becomes seriously ill or dies suddenly, or after experiencing or hearing about natural disasters such as earthquakes or plane crashes. According to subconscious language, twilight symbolizes the imminent death, so when a person is at twilight, the symptoms of anxiety are involuntarily aggravated. 4, some anxiety patients are taking sleeping pills or drugs with sedative effects, these drugs are often taken at night or before bedtime, and by the next evening, the concentration of the drugs in the body has been significantly reduced, resulting in a weakening of the effect of the drugs and a rebound of the anxiety symptoms suppressed by the drugs.