Old cold leg is mostly triggered by cold, strain or trauma, with recurrent, long-lasting sore and numb pain in the legs (mostly knee joints), collectively known as old cold leg. It differs from rheumatoid arthritis in that it often does not cause deformities of the joints and does not have systemic damage such as interstitial lung fibrosis and iritis. Laboratory tests for rheumatoid factor are generally negative (10%-15% positive rate in normal elderly people) and the prognosis is good. In addition to pain-relieving drugs, Chinese herbal medicine can be used to improve the symptoms by warming the Yang and promoting the circulation of blood and dispersing cold. In addition, acupuncture, moxibustion, Chinese medicine fumigation, warm acupuncture, Chinese medicine collapse, fire therapy, etc. can be used to increase the clinical efficacy.