The difference between primary and secondary osteoporosis is as follows: 1. Etiology: primary osteoporosis is a degenerative disease that occurs with age and includes postmenopausal osteoporosis, senile osteoporosis and idiopathic osteoporosis; secondary osteoporosis is osteoporosis due to any diseases and drugs that affect bone metabolism and other clear causes; 2. Treatment: patients with secondary osteoporosis need treatment for the primary disease in addition to osteoporosis.