Diabetes, Heartburn, and Fast Heart Rate: What These Symptoms Can Mean for Your Health 

Living with diabetes changes the way your body talks to you, especially your heart. Heart problems that cause dramatic chest pain in some people may feel very different in someone with diabetes.

Sometimes the only warning sign is heartburn, a nagging sense of indigestion, or a racing heart that doesn’t feel right.

Why Heart Trouble Can Feel Like Heartburn

Your heart and your esophagus (the tube that carries food to your stomach) share many of the same nerve pathways. When those nerves are affected by diabetes, your brain can confuse where the signal is coming from.

This overlap means a heart problem may feel like a stomach problem.

For someone with diabetes, a heart attack or reduced blood flow to the heart may feel like:

• Burning in the chest
• Indigestion after a meal
• A heavy or full feeling in the upper stomach
• Nausea, with or without vomiting

If you already live with reflux or heartburn, it can be very easy to assume:

"It’s just my stomach acting up again."

However, in diabetes, new or different indigestion can be a warning sign of heart disease.

How Diabetes Changes Your Heart

Diabetes can affect the heart in several ways, often long before symptoms appear.

1. The Heart Can Become Stiffer Over Time

High blood sugar can damage small blood vessels and the heart muscle itself. Over time, this can cause the heart muscle to become thicker and stiffer. When that happens, the heart has trouble relaxing between beats.

You may notice:

• Shortness of breath, especially with activity or when lying flat
• Swelling in the legs or feet
• Feeling unusually tired

2. Nerves That Signal Heart Pain May Not Work As Well

Diabetes can damage the autonomic nerves, the nerves that control your organs without you thinking about it. That includes the nerves that help your brain recognize when your heart is not getting enough blood.

Because of this nerve damage, a heart attack in someone with diabetes may not cause classic chest pain. Instead, it may feel like:

• Heartburn or indigestion
• Nausea or vomiting
• Discomfort in the upper stomach
• Jaw, neck, or back pain
• Sudden, unexplained fatigue
• Shortness of breath

This is one reason heart disease can be more dangerous in people with diabetes: serious problems can be more challenging to recognize.

3. Blood Vessels May Be Narrowed or Damaged

Over time, high blood sugar, high blood pressure, and unhealthy cholesterol levels can damage the lining of blood vessels, leading to accelerated plaque buildup in the arteries.

Narrowed arteries:

• Reduce blood flow to the heart muscle
• Increase the risk of chest pain (angina)
• Raise the risk of heart attack and heart failure

Why Heart Trouble Can Feel Like Heartburn

Your heart and your esophagus (the tube that carries food to your stomach) share many of the same nerve pathways. When those nerves are affected by diabetes, your brain can confuse where the signal is coming from.

This overlap means a heart problem may feel like a stomach problem.

For someone with diabetes, a heart attack or reduced blood flow to the heart may feel like:

• Burning in the chest
• Indigestion after a meal
• A heavy or full feeling in the upper stomach
• Nausea, with or without vomiting

If you already live with reflux or heartburn, it can be very easy to assume:

"It’s just my stomach acting up again."

However, in diabetes, new or different indigestion can be a warning sign of heart disease.

Important Note About Antacids

If heartburn or chest burning improves after you take an antacid, that does not guarantee the cause was only reflux.

Pain from the heart can come and go. Sometimes both reflux and heart problems occur simultaneously. Relief from an antacid should never be used as a test to rule out a heart problem, especially if you have diabetes.

If you aren't sure if pain or discomfort you're feeling is indigestion or a heart attack, get medical help immediately. It's always better to be safe than sorry.

What If Your Heart Suddenly Starts Racing?

Heart problems in diabetes may also show up as a sudden, uncomfortable racing heartbeat.

Doctors call this tachycardia—a heart rate that is faster than normal at rest.

A single number is not the whole story. A heart rate over 100 beats per minute (BPM) at rest can be a concern in adults, but context matters. What you were doing, how you feel, and how long it lasts are just as important as the number of beats.

You may notice:

• A pounding or racing heartbeat that comes out of nowhere
• A feeling that your heart is “flip-flopping” or skipping beats
• A fast pulse at rest that does not settle down after a few minutes

These episodes can feel scary—and they are a signal that something needs attention.

Fast Heart Rate: When to Call 911

A fast heart rate becomes an emergency when it affects your heart's ability to pump blood.

Call 911 or seek emergency care right away if a racing heart is sustained (lasts more than a few minutes) and you notice any of the following:

• Chest pain, pressure, or tightness
• Shortness of breath or trouble speaking in full sentences
• Feeling faint or passing out
• Confusion, trouble thinking clearly, or feeling "out of it"
• Very low blood pressure numbers at home
• Sudden, cold, clammy sweating

In these situations, the exact heart rate number matters less than how sick you feel. A person with a heart rate of 130 who is faint and confused may be in more danger than someone with a heart rate of 170 who feels alert and stable.

If you are ever unsure, treat it as an emergency and get checked.

When a Fast Heart Rate Is a Symptom of Something Else

Not every racing heart is caused by a primary rhythm problem in the heart itself. Sometimes your heart is simply responding to another stress in the body.

Common examples include:

• Severe anemia (low red blood cells)
• Infection or high fever
• Dehydration
• Overactive thyroid
• Uncontrolled blood sugar or other metabolic stress

In these cases, the fast heart rate is like an alarm bell. Treating the underlying problem—such as infection, dehydration, or thyroid disease—is what protects your heart in the long run.

Because people with diabetes are at higher risk for infections, blood sugar swings, and other stresses, this connection is especially important.

Protecting Your Heart When You Have Diabetes

While all of this can sound overwhelming, the steps that protect your heart are clear and important.

You can:

• Keep blood sugar in your target range
• Take blood pressure and cholesterol medicines as prescribed
• Stay active most days of the week
• Avoid smoking and tobacco products
• Keep your regular checkups and recommended heart tests

Most importantly, listen to changes in your body and report them to your provider.

When to Get Immediate Help

If you live with diabetes, treat the following as reasons to seek urgent or emergency care:

• New or unusually strong heartburn or indigestion, especially if it feels different from your usual reflux
• Sudden nausea, vomiting, or upper stomach pain that "just feels wrong"
• A racing heart that does not slow down and is paired with chest pain, shortness of breath, fainting, confusion, or heavy sweating
• Sudden, unexplained exhaustion or shortness of breath with simple activities

When in doubt, it is safer to get checked. A quick ECG and blood test can often tell very quickly whether your symptoms are related to your heart.

The Bottom Line

Diabetes changes the way your heart sends and receives warning signals. Heart problems that cause dramatic chest pain in some people may show up as heartburn, indigestion, nausea, or a racing heart in someone with diabetes.

You do not have to sort this out alone. If something feels new, different, or alarming, especially in your chest, upper stomach, or if you experience a change in your heartbeat, reach out for care. Getting answers early is one of the most effective ways to protect your heart and your future.