**Question:** Which of the following is seen in osteoporosis -

A. Bone resorption
B. Bone formation
C. Decreased bone density
D. Increased bone density

**Core Concept:** Osteoporosis is a skeletal disorder characterized by decreased bone density, leading to brittle bones that are more prone to fractures. Osteoporosis primarily affects bone mineral density (BMD), which is determined by a balance between bone resorption and bone formation.

**Why the Correct Answer is Right:** Osteoporosis results from an imbalance between bone resorption and bone formation. Specifically, the balance shifts towards increased bone resorption, leading to a decrease in bone mineral density. This is reflected in the correct answer, **C. Decreased bone density**.

**Why Each Wrong Option is Incorrect:**

A. **Bone resorption (Option A)** is essential for maintaining bone homeostasis by removing damaged or old bone tissue. However, in osteoporosis, bone resorption is excessive, leading to a decrease in bone density and overall skeletal integrity.

B. **Bone formation (Option B)** is a crucial process for bone remodeling and repair. However, in osteoporosis, bone formation is inadequate, contributing to the decrease in bone density and increased fracture risk.

D. **Increased bone density (Option D)** is not seen in osteoporosis as the disease results in decreased bone density, making bones weak and prone to fractures.

**Clinical Pearl:** Osteoporosis is a significant public health issue affecting millions of people globally, particularly postmenopausal women and the elderly. Regular screening for bone mineral density and lifestyle interventions, such as exercise and calcium/vitamin D supplementation, are essential preventive measures. Treatment options include pharmacological agents like bisphosphonates and hormone replacement therapy for women. Early detection and management of osteoporosis can significantly reduce the risk of fractures and improve patient outcomes.