Cold is the primary cause of chilblains, but in addition, factors such as the patient's own skin moisture, abnormalities in peripheral microvessels, autonomic nerve dysfunction, malnutrition, anemia, endocrine disorders, etc., may also participate in the development of the disease. Other factors such as lack of exercise, hyperhidrosis of the hands and feet, overly tight socks and shoes, and long-term outdoor work may also contribute to the occurrence of chilblains. Therefore, chilblains are actually a multifactorial disease, making it prone to recurrence.