Primary / idiopathic causes

Primary osteoporosis is classified as:

• age-related or senile:
  • occurs in elderly men and women, around the seventh or eighth decade
  • associated with a steady rate of bone loss of about 0.5% per year
    
    
• post-menopausal:
  • lack of oestrogen reduces osteoblastic activity
  • increased bone resorption as osteoclast action is no longer balanced
    
    
• not related to age:
  • idiopathic juvenile or young adult onset
  • osteoporosis of pregnancy