In tetany, which substance is typically found at a low level in the blood?

In tetany, which refers to a condition characterized by muscle spasms and cramps, calcium is typically found at low levels in the blood. This condition arises due to hypocalcemia, which is a deficiency of calcium in the bloodstream. Calcium plays a critical role in muscle contraction and nerve function, and when its levels are insufficient, it can lead to increased neuromuscular excitability and the hallmark symptoms of tetany.

In contrast, glucose, sodium, and potassium levels are not directly related to the mechanism of tetany. Glucose is primarily concerned with energy metabolism, sodium is crucial for fluid balance and nerve function, and potassium is vital for maintaining normal cell function and electrical activity of muscles and nerves. While imbalances in these electrolytes may cause other health issues, calcium deficiency is specifically linked to the occurrence of tetany.