Final answer:
The common side effect of thiazide diuretics is Hypokalemia, which is a low level of potassium in the blood.
Step-by-step explanation:
The common side effect of thiazide diuretics is Hypokalemia, which is a low level of potassium in the blood. Thiazide diuretics inhibit the reabsorption of sodium and chloride ions in the kidney, which leads to increased excretion of these ions along with water. However, along with the excretion of sodium and chloride, there is also loss of potassium, resulting in hypokalemia.