What are common signs and symptoms of hypernatremia?

Hypernatremia occurs when there is an excessive concentration of sodium in the blood, which typically can be caused by factors such as dehydration, excess sodium intake, or certain medical conditions. The correct response highlights critical neurological and psychological effects associated with hypernatremia.

Increased serum sodium levels lead to osmotic imbalances that can affect cellular function, especially in the brain. When hypernatremia develops, cells lose water to try to equalize the sodium concentration, leading to cellular dehydration. Common signs include changes in consciousness, which can manifest as confusion, agitation, or decreased responsiveness, as well as irritability. These symptoms arise due to the direct effect of hypernatremia on the central nervous system and the disruption in neuronal function.

In contrast, the other options present symptoms that are not characteristically associated with hypernatremia. Weight gain and hypertension are more associated with fluid retention and conditions like heart failure, while increased appetite and fatigue can be seen in various other metabolic or endocrine disorders. Similarly, skin rashes and fever typically indicate infectious or dermatological conditions rather than an electrolyte disturbance. Thus, the signs of change in consciousness and irritability effectively reflect the neurological implications of hypernatremia.