Separation anxiety disorder is a psychological disorder in which emotional disturbances occur after separation. The condition is common in children, and a few adults also experience separation anxiety disorder, with abnormal mental and emotional manifestations being the most typical, such as anxiety, fear, worry, dread, depression, poor diet, insomnia, dreaminess, mood swings, etc., even affecting life and work. In general, the experience of separation anxiety in childhood is a major trigger for the onset of separation anxiety disorder in adults. Separation from one’s parents and family in childhood to an unfamiliar environment makes separation anxiety easy to occur. This abnormal presentation in childhood may continue into adulthood without active intervention and treatment. When experiencing similar situations or feelings in adulthood, one is prone to anxiety, depression, and other disturbing emotions. These negative mood swings may then affect other parts of the body and may be accompanied by some digestive symptoms such as nausea, vomiting, and in severe cases, diarrhea. It may also be accompanied by central nervous symptoms, such as hand tremors, dizziness, headaches, and insomnia. Adults with separation anxiety disorder will be more insecure, so it is recommended that family members and friends around them should give enough care and companionship to make the patient feel warmth from their surroundings. If this happens to parents after their children have traveled far away, children should also care for their parents appropriately and can improve their feelings of anxiety after separation through frequent contact. In addition, for the treatment of separation anxiety disorder in adults, systematic psychotherapy may be more effective compared to medication. Therefore, early psychological intervention is recommended for those with these symptoms to avoid more severe emotions or symptoms.