| Osteoporosis | Osteoarthritis | |
| What is affected? | Bones, which become more fragile and more likely to break | Joints, especially weight-bearing joints (knees, feet, hips, and back) |
| Whom does it affect? | 4 of 5 people suffering from osteoporosis are women occurs most commonly after the age of 45 | Men and women equally; usually occurs after age 45 |
| Why does it happen? | Loss of bone mass, related to certain risk factors | Join structure weaken and wear down |