Over activity of which hormone causes Cushing's syndrome?

Options

A. Cortisol
B. Oxytocin
C. Aldostrone
D. Thyroxine

Answer

To solve the question regarding which hormone's overactivity causes Cushing's syndrome, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Cushing's Syndrome**:
- Cushing's syndrome is a condition that arises due to excessive levels of certain hormones in the body. It is characterized by a variety of symptoms including weight gain, high blood pressure, and changes in mood.

2. **Identifying the Hormones**:
- The question provides several hormone options: Cortisol, Oxytocin, Aldosterone, and Thyroxine. We need to analyze each one to determine which is linked to Cushing's syndrome.

3. **Analyzing Each Hormone**:
- **Cortisol**: This hormone is produced by the adrenal glands and is crucial for stress response, regulating metabolism, and maintaining blood sugar levels. Excessive production of cortisol is known to lead to Cushing's syndrome.
- **Oxytocin**: This hormone is primarily involved in childbirth and lactation. It does not relate to Cushing's syndrome.
- **Aldosterone**: This hormone helps regulate sodium and water balance in the body, affecting blood pressure but is not directly linked to Cushing's syndrome.
- **Thyroxine**: This is a thyroid hormone that regulates metabolism and energy levels. It is not associated with Cushing's syndrome.

4. **Conclusion**:
- After analyzing all the hormones, it is clear that the overactivity of **Cortisol** is responsible for causing Cushing's syndrome. Therefore, the correct answer is **Cortisol**.

### Final Answer:
Cortisol