We put our heart into so much of daily life, but diabetes can place extra pressure on the heart without obvious symptoms at first. I want you to understand that heart failure does not mean the heart has stopped. It means the heart cannot pump blood effectively enough, or cannot fill normally, to meet the body’s needs.
Quick Answer
Diabetes increases the risk of heart failure, particularly when high blood pressure, kidney disease, coronary artery disease, obesity, or long-term high blood glucose is also present. Watch for new shortness of breath, swollen feet or ankles, rapid weight gain, unusual fatigue, reduced exercise tolerance, or difficulty breathing when lying flat. These symptoms need medical assessment; severe breathlessness, chest pain, fainting, blue lips, or confusion require emergency help.
What Is Heart Failure?
Heart failure is a chronic condition in which the heart cannot pump or fill efficiently enough to supply the body. Blood and fluid may back up in the lungs or other tissues, causing breathlessness and swelling. The condition may involve:
- Reduced ejection fraction (HFrEF): the heart’s main pumping chamber contracts less strongly.
- Mildly reduced ejection fraction (HFmrEF): pumping function falls between reduced and preserved ranges.
- Preserved ejection fraction (HFpEF): the percentage pumped may look relatively preserved, but the heart is stiff and does not fill normally.
Heart failure can develop slowly or worsen suddenly. It is not the same as a heart attack, although a heart attack can damage the heart and cause heart failure.
Why Are Diabetes and Heart Failure Connected?
Blood vessels
Diabetes accelerates atherosclerosis and increases the risk of coronary artery disease and heart attack, which can weaken the heart muscle.
Blood pressure and kidneys
High blood pressure and diabetic kidney disease make the heart work harder and encourage sodium and fluid retention.
Heart muscle metabolism
Insulin resistance, inflammation, oxidative stress, and abnormal energy use can contribute to structural and functional changes in the heart.
Risk is also influenced by age, obesity, smoking, sleep apnea, abnormal cholesterol, atrial fibrillation, valve disease, and previous cardiovascular disease. Good glucose control is important, but heart protection requires attention to the complete risk profile—not glucose alone.
Heart Failure Symptoms You Should Not Ignore
- Shortness of breath during activity, at rest, or when lying flat
- Waking at night gasping or needing extra pillows to breathe
- Swelling of the feet, ankles, legs, or abdomen
- Rapid weight gain that may indicate fluid accumulation
- Unusual tiredness, weakness, or reduced ability to exercise
- Persistent cough or wheeze, especially when lying down
- Fast or irregular heartbeat
- Reduced appetite, nausea, difficulty concentrating, or confusion
How Is Heart Failure Diagnosed?
Symptoms alone cannot confirm heart failure. Your clinician will review when symptoms began, whether they are changing, your diabetes and heart history, medications, weight pattern, blood pressure, pulse, oxygen level, lungs, heart sounds, neck veins, and swelling.
Tests may include an electrocardiogram, chest imaging, blood tests, kidney function and electrolytes, BNP or NT-proBNP, and an echocardiogram to examine heart structure, valves, filling, and ejection fraction. Other investigations may be needed to look for coronary artery disease, rhythm problems, or alternative causes of breathlessness.
Diabetes Medicines and Heart Failure
| Medication group | What you should know |
|---|---|
| SGLT2 inhibitors | Medicines with proven benefit can reduce worsening heart failure and cardiovascular death in suitable people with type 2 diabetes and either reduced or preserved ejection fraction. They also require education about dehydration, genital infections, and the uncommon risk of ketoacidosis. |
| Thiazolidinediones pioglitazone, rosiglitazone | These medicines can cause fluid retention and may worsen heart failure. Their suitability should be reviewed if heart failure or concerning swelling develops. |
| Some DPP-4 inhibitors | The FDA heart-failure warning specifically applies to saxagliptin and alogliptin. It does not mean that every medicine in the DPP-4 class has the same demonstrated risk. |
| Metformin | It may often be continued in stable heart failure when kidney function is adequate, but it is generally avoided during unstable or hospitalized heart failure. |
How Is Heart Failure Treated in a Person With Diabetes?
Treatment depends on the type of heart failure, ejection fraction, symptoms, kidney function, potassium, blood pressure, rhythm, and other medical conditions. A plan may include:
- Diuretics to relieve fluid congestion
- An ARNI, ACE inhibitor, or ARB when indicated
- Evidence-based beta-blockers
- Mineralocorticoid receptor antagonists with kidney and potassium monitoring
- SGLT2 inhibitors with demonstrated heart-failure benefit
- Treatment of high blood pressure, coronary disease, rhythm disorders, valve disease, obesity, sleep apnea, and kidney disease
- Selected devices or advanced therapies for certain patients
Potassium-sparing medicines such as spironolactone are not simple home treatments. They can raise potassium and worsen kidney problems, so blood tests and professional supervision are essential.
How Can You Reduce Heart Failure Risk?
I encourage you to protect more than your glucose number. Work with your medical team to:
- Keep blood pressure within your individualized target
- Manage cholesterol and take prescribed cardiovascular medicines consistently
- Check kidney function and urine albumin regularly
- Avoid smoking and secondhand smoke
- Choose a balanced eating pattern and discuss sodium intake if swelling or heart failure is present
- Stay physically active at a level considered safe for your heart and overall health
- Address obesity, poor sleep, and possible sleep apnea
- Ask whether your diabetes treatment also offers proven heart and kidney protection
Related Questions
Does reducing blood sugar make diabetic foot swelling disappear?
Better glucose control protects the circulation, kidneys, and heart over time, but swelling may have another cause and may not disappear when one glucose reading improves. Read Dr. Albana’s full answer: Does reducing blood sugar reduce foot swelling?
Can you have heart failure with a normal ejection fraction?
Yes. In HFpEF, the heart’s ejection fraction may be preserved, but the heart muscle is stiff and does not fill normally. Symptoms can still be serious and require treatment.
Can heart failure improve?
Symptoms and heart function can improve for many people with early diagnosis, treatment of the cause, guideline-directed medication, and careful follow-up. Heart failure still requires ongoing management even when you feel better.
Is ankle swelling always caused by the heart?
No. Kidney disease, vein problems, medication effects, liver disease, infection, injury, and blood clots can also cause swelling. A clinician needs to identify the cause.
Related Resources
References
- Cardiovascular Disease and Risk Management: Standards of Care in Diabetes—2026. American Diabetes Association.
- 2022 ACC/AHA/HFSA Guideline for the Management of Heart Failure. Heart Failure Society of America.
- Warning Signs of Heart Failure. American Heart Association.
- DPP-4 Inhibitors and Heart Failure: Some Reassurance, Some Uncertainty. Diabetes Care.