Addison's disease results from:

Options

A. hypertrophy of gland
B. hypo-secretion of adrenal cortex
C. hyperactivity of cells of Leydig
D. none of the above

Answer

### Step-by-Step Solution:

1. **Understanding Addison's Disease**:
- Addison's disease is a disorder that occurs when the adrenal glands do not produce enough hormones. It primarily affects the adrenal cortex, which is the outer layer of the adrenal glands.

2. **Identifying the Cause**:
- The disease results from damage to the adrenal glands, leading to a deficiency in hormone production. The key hormones affected include cortisol and aldosterone.

3. **Analyzing the Options**:
- **Hypertrophy of Gland**: This refers to an increase in the size of the gland, which is not the cause of Addison's disease.
- **Hyposecretion of Adrenal Cortex**: This indicates that there is insufficient hormone production from the adrenal cortex, which aligns with the characteristics of Addison's disease.
- **Hyperactivity of Cells of Leydig**: Leydig cells are involved in testosterone production in the testes, and their activity is not related to Addison's disease.
- **None of the Above**: This option is incorrect as we have identified a valid cause.

4. **Conclusion**:
- The correct answer is **hyposecretion of adrenal cortex**, which is the result of damage to the adrenal glands leading to insufficient hormone production.

### Final Answer:
Addison's disease results from **hyposecretion of adrenal cortex**.

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