Tetany is characterised by which of the following?

Options

A. Lowered blood `Ca^(2+)`
B. Enhanced blood `Na^+`
C. Enhanced blood glucose
D. Enhanced blood `Ca^(2+)`

Answer

**Step-by-Step Solution:**

1. **Understanding Tetany**: Tetany is a medical condition characterized by involuntary muscle contractions, cramps, and spasms. It is often associated with disturbances in calcium levels in the body.

2. **Identifying Causes**: One of the primary causes of tetany is a malfunction of the parathyroid glands, which are responsible for regulating calcium levels in the blood. When these glands do not function properly, it can lead to low calcium levels (hypocalcemia).

3. **Recognizing Symptoms**: The symptoms of tetany include muscle cramps, spasms, and tremors. These symptoms are directly linked to low levels of calcium in the bloodstream.

4. **Analyzing Options**:
- Option 1: Low blood calcium - This is consistent with tetany, as low calcium levels can lead to muscle spasms.
- Option 2: High blood sodium - This is not related to tetany.
- Option 3: High blood glucose - This is also not related to tetany.
- Option 4: High blood calcium - This condition is not associated with tetany.

5. **Conclusion**: Based on the analysis, the correct answer is that tetany is characterized by low blood calcium levels.

**Final Answer**: Option 1: Low blood calcium.

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