Tetany is caused by

Options

A. hyperparathyroidism
B. hypoparathyroidism
C. hyperthyroidism
D. Hypothyroidism

Answer

**Step-by-Step Solution:**

1. **Understanding Tetany**: Tetany is a medical condition characterized by muscle spasms, cramps, and convulsions. It is primarily associated with abnormal calcium levels in the blood.

2. **Role of Parathyroid Hormone (PTH)**: The parathyroid glands, located on the dorsal surface of the thyroid gland, secrete parathyroid hormone (PTH). This hormone plays a crucial role in regulating calcium levels in the blood. It increases blood calcium levels by promoting bone resorption, enhancing intestinal absorption of calcium, and reducing renal excretion of calcium.

3. **Causes of Tetany**: Tetany is primarily caused by hypocalcemia, which is a deficiency of calcium in the blood. This condition can occur due to insufficient secretion of PTH, which is seen in hypoparathyroidism.

4. **Identifying the Correct Condition**: Among the options provided, hypoparathyroidism is the condition that leads to decreased levels of PTH, resulting in low blood calcium levels (hypocalcemia). This deficiency causes sustained muscle contractions, leading to the symptoms of tetany.

5. **Conclusion**: Therefore, tetany is caused by hypoparathyroidism, as it leads to decreased calcium levels in the blood, resulting in muscle spasms and other related symptoms.

**Final Answer**: Tetany is caused by hypoparathyroidism.

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