Final answer:
Hyponatremia, with a sodium level below 135 mEq/L, can cause symptoms such as headache, nausea, confusion, muscle weakness, fatigue, seizures, and coma. These can result from both the dilutional effect of excess body water and the absolute loss of sodium through various mechanisms like sweating, vomiting, or use of diuretics.
Step-by-step explanation:
The signs and symptoms of hyponatremia, which is a condition of below-normal sodium concentration in the blood (specifically below 135 mEq/L), can include a variety of manifestations. The symptoms can range from headache, nausea, and confusion, which are related to the effect of hyponatremia on the brain, to muscle weakness and fatigue due to the diminished function of muscles. More severe symptoms include seizures and coma, which can occur due to significant shifts of water into brain cells, leading to cerebral edema. Thus, the correct answer to the question is 4) All of the above.
Hyponatremia can also lead to decreased blood volume and circulatory failure, often as a result of conditions like acute vomiting, diarrhea, excessive sweating, or the use of diuretics. Furthermore, water intoxication, which involves excessive water retention, can also lead to this condition, resulting in similar neurological symptoms.