Taking hydrochlorothiazide (HCTZ) may raise your blood sugar a little. Everyone is different. On average, blood sugar levels go up 1 to 5 mg/dL after starting HCTZ. Although it is rare, in studies, people taking HCTZ were slightly more likely to get diabetes than people who did not.
HCTZ is a good choice for some people who need to lower their blood pressure. Lowering blood pressure lowers the risk of heart disease. This is important even if the blood sugar goes up slightly when taking HCTZ. The benefit of the medicine outweighs the small rise in blood sugar.
If you have diabetes and take HCTZ you may need to adjust your diabetes medicine. Sometimes, your doctor will have you raise your dose a little. This will help keep your blood sugar at a healthy level.