Question: How does furosemide affect blood glucose level? Does it lower or increase glucose levels? If I am diabetic, can I still take it?
Furosemide can increase blood glucose or reduce glucose tolerance in some people, although the effect is often small and does not happen to everyone. It is not used to lower blood sugar.
People with diabetes can take furosemide when it is medically necessary and prescribed. Do not stop it on your own; instead, monitor glucose and follow your clinician's plan for kidney-function and electrolyte testing.
Furosemide is a loop diuretic, sometimes called a water pill. It helps the kidneys remove extra salt and water and is commonly prescribed for swelling, heart failure, kidney or liver disease, and sometimes high blood pressure.
Official medicine information lists increased blood glucose and altered glucose tolerance as possible adverse effects. The response varies between patients, and the exact reason for a higher reading may not be clear. The illness being treated, stress, infection, dehydration, changes in food intake, kidney function, and other medicines can also affect glucose.
For this reason, one high reading does not prove that furosemide is the only cause. Record the timing of your dose, meals, symptoms, and readings using a blood sugar log, then review the pattern with your clinician.
Yes. Many people with diabetes take furosemide safely because controlling fluid overload may be essential for the heart, lungs, kidneys, or blood pressure. Diabetes is a reason for closer monitoring, not an automatic reason to avoid the medicine.
After starting furosemide or changing the dose, your clinician may advise additional checks of:
Do not change furosemide, insulin, metformin, or another diabetes medicine without medical advice. Our guide to diabetes medication safety and side effects explains why medication changes should be reviewed together.
Contact your clinician if glucose becomes repeatedly higher than your personal target after starting or increasing furosemide, or if you develop unusual thirst, frequent urination, marked fatigue, dizziness, muscle cramps, weakness, reduced urine output, or signs of dehydration. Bring your glucose record and a complete medicine list.
You can compare readings with our guide to blood sugar levels by time of day, but your own treatment targets may differ.
Seek urgent medical care for severe shortness of breath, chest pain, fainting, severe confusion, very little urine, severe dehydration, or very high glucose with vomiting, abdominal pain, deep or rapid breathing, fruity-smelling breath, or moderate/high ketones. Do not stop prescribed furosemide while waiting for advice unless an emergency clinician tells you to do so.
Answered by: Dr. Albana Greca Sejdini, MD, MMedSc
Medically reviewed by: Dr. Ruden Cakoni, MD, Endocrinologist
Last reviewed: July 2026
Medical disclaimer: Educational only—not personal medical advice. Diagnosis and treatment should come from a qualified clinician who knows the patient's medical history.
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