Renal calculi are formed due to

Options

A. Calcium oxalate crystals accumulation
B. Bacterial infection
C. Clotting of blood
D. Presence of hard particles in food

Answer

### Step-by-Step Solution:

1. **Understanding Renal Calculi**:
- Renal calculi, commonly known as kidney stones, are hard deposits that form in the kidneys. They are primarily composed of minerals and salts.

2. **Composition of Renal Calculi**:
- The most common type of renal calculi is made up of calcium oxalate crystals. These crystals form when there is an excess of calcium and oxalate in the urine.

3. **Causes of Formation**:
- The formation of renal calculi can be attributed to several factors:
- **Diet**: High intake of foods rich in oxalate can lead to increased levels of calcium oxalate in the urine.
- **Obesity**: Excess body weight can contribute to the formation of kidney stones.
- **Medical Conditions**: Certain underlying medical conditions can lead to the accumulation of minerals in the kidneys.
- **Calcium Supplements**: Prolonged use of calcium supplements can also result in the formation of stones.

4. **Symptoms and Consequences**:
- Smaller kidney stones may pass out of the body without causing any symptoms. However, larger stones can cause significant pain, blockage in the ureter, painful urination, and severe abdominal pain.

5. **Evaluating the Options**:
- **Calcium Oxalate Crystals Accumulation**: This is the correct reason for the formation of renal calculi.
- **Bacterial Infection**: This does not directly lead to the formation of kidney stones.
- **Clotting of Blood**: This refers to the clumping of blood cells and is not related to kidney stones.
- **Presence of Hard Particles in Food**: While hard particles may exist, they do not specifically refer to calcium oxalate crystals.

6. **Conclusion**:
- The correct answer is that renal calculi are formed due to the accumulation of calcium oxalate crystals.