Final answer:
A sodium level of 129 mEq/L is indicative of hyponatremia, which can cause cellular swelling, decreased oxygen transportation by red blood cells, potential brain damage, and other serious health issues.
Step-by-step explanation:
A sodium level of 129 mEq/L is an indication of hyponatremia, which is a lower-than-normal concentration of sodium in the blood. Individuals with hyponatremia are at increased risk for several complications. This condition can lead to cellular swelling as water enters cells via osmosis to balance the lower concentration of sodium in the extracellular fluid (ECF).
Specifically the swelling of red blood cells can decrease their oxygen-carrying efficiency, and the swelling of neurons in the brain can result in brain damage or even death. Other risks associated with hyponatremia include confusion, lethargy seizures, muscle cramps or weakness, nausea and headaches. Therefore a client with a sodium level of 129 mEq/L is at increased risk for c. decreased Na+ levels and its associated complications.