Final answer:
Hyponatremia is a condition characterized by decreased plasma sodium concentration. It can be caused by multiple factors including excessive water accumulation in the body and various medical conditions. In hyponatremia, there is an imbalance of sodium in the body's fluid compartments, leading to swelling of cells.
Step-by-step explanation:
Hyponatremia is a condition characterized by a decrease in plasma sodium concentration. It is usually caused by excess water accumulation in the body, which dilutes the sodium. This can occur due to various factors such as decreased intake of sodium, excessive sweating, vomiting, or diarrhoea, use of diuretics, excessive urine production in diabetes, and acidosis. In hyponatremia, there is an imbalance of sodium in the body's fluid compartments, leading to increased entry of water into cells. This causes cells to swell, including red blood cells, which may result in decreased oxygen-carrying efficiency and brain damage or death if neurons in the brain swell.