Osteoporosis is a medical condition that causes porous and weak bones leading to fractures. This article discusses its causes, symptoms, prevention and treatment. It affects about 1.2 million people in Australia and is more common in women after menopause. The symptoms include stooping, loss of height, and fractures that occur more easily than expected. The causes include age, reduced estrogen levels, and lifestyle factors such as smoking, alcohol, and low intake of calcium and vitamin D. Osteoporosis has a serious impact on quality of life, happiness, and health. Prevention includes regular weight-bearing and resistance exercises, healthy eating, limiting alcohol intake, and quitting smoking. Treatment includes taking drugs to increase vitamin D and calcium levels in the body.