**Question:** Osteoporosis is characterized by all the following except -
**Correct Answer:** B.

**Core Concept**
Osteoporosis is a systemic skeletal disorder characterized by a reduction in bone mass and density, leading to an increased risk of fractures. It is a complex condition involving alterations in bone metabolism, structure, and function.

**Why the Correct Answer is Right**
Option B is incorrect because osteoporosis is primarily characterized by a decrease in bone mass and density, not an increase. This decrease is due to an imbalance between bone resorption and bone formation, leading to a net loss of bone tissue. The underlying pathophysiology involves the activation of osteoclasts, which break down bone matrix, and the inhibition of osteoblasts, which form new bone tissue.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because osteoporosis is indeed associated with an increased risk of fractures, particularly in the spine, hip, and wrist. This is due to the weakened bone structure and decreased bone density.
* **Option C:** This option is incorrect because osteoporosis is characterized by a decrease in bone mineral density (BMD), which is a key diagnostic criterion for the condition. BMD is measured using techniques such as dual-energy X-ray absorptiometry (DXA).

**Clinical Pearl / High-Yield Fact**
One key aspect of osteoporosis management is the use of bisphosphonates, which inhibit osteoclast activity and reduce bone resorption. It is essential to choose the correct bisphosphonate and dosing strategy to maximize efficacy and minimize side effects.

**Correct Answer:** B.