Final answer:
Dehydration can cause medication levels to become higher than normal due to reduced blood volume. This condition concentrates the medication because there is less water in the body to dilute it, potentially leading to increased toxicity.
Step-by-step explanation:
The condition that may make medication levels higher than normal is dehydration. Dehydration occurs when there is a loss of water from the body without adequate replacement. It reduces blood volume and causes the water within cells to move into the blood, making medication concentrations relatively higher due to decreased blood volume. This state can be caused by various factors such as heat exposure, vomiting, diarrhea, excessive sweating, or conditions like diabetes mellitus or kidney disease.
Dehydration can lead to symptoms like dizziness, low blood-pressure, and in severe cases, loss of consciousness. Compounded by dehydration, medication toxicity could be exacerbated due to the increased concentration of the drug in the bloodstream relative to the water content of the body.