The single most dangerous thing you can do during a heart attack is wait to see if the symptoms go away. Every minute of delay increases the amount of heart muscle that dies, and the difference is stark: patients who received care within one hour had roughly five times the survival benefit compared to those who waited more than 12 hours. Beyond waiting, there are several specific actions that can make a heart attack worse or delay life-saving treatment.
Don’t Wait It Out
The most common and most deadly mistake is convincing yourself it’s not serious. People frequently misinterpret heart attack symptoms as indigestion, muscle strain, or anxiety, and decide to lie down and see if it passes. This is especially true for women and people with diabetes, who are more likely to experience symptoms that don’t match the “classic” picture of crushing chest pain. In one study, 85% of women having a heart attack presented with what doctors call atypical symptoms: dizziness, sweating, shortness of breath, nausea, back pain, or extreme fatigue rather than obvious chest pressure.
Denial plays a major role. Research on why patients delay seeking care consistently finds that people downplay the severity of their symptoms, attribute them to something harmless, or tell themselves they’ll feel better soon. The heart muscle begins dying within minutes of losing blood flow, and the window for restoring it narrows quickly. Treatment within the first hour saves approximately 107 lives per 1,000 patients. After 12 hours, that number drops to 21 per 1,000.
Don’t Drive Yourself to the Hospital
This is one of the most repeated pieces of emergency guidance, and for good reason. During a heart attack, you can lose consciousness without warning. If that happens behind the wheel, you endanger yourself and everyone on the road. The OHSU Knight Cardiovascular Institute puts it plainly: driving yourself is dangerous for you and others, it could delay your treatment, and you could lose consciousness and cause an accident.
Calling 911 instead of driving also gives you a significant medical advantage. Paramedics can begin treatment in the ambulance, including monitoring your heart rhythm and delivering a shock if your heart goes into a fatal rhythm called ventricular fibrillation. In one study of heart attack patients transported by ambulance, 27 patients received a life-saving electrical shock during transit and 52 received CPR. None of that is possible in the passenger seat of a car on the highway. EMS can also transmit your heart data to the hospital ahead of your arrival so a cardiac team is assembled and ready when you get there.
Don’t Eat, Drink, or Take the Wrong Medication
If you think you’re having a heart attack, don’t eat or drink anything. There’s a practical reason: if you need an emergency procedure (which many heart attack patients do), having food in your stomach increases the risk of vomiting and choking while sedated. The only exception is medication that has been specifically prescribed to you for a cardiac event.
Aspirin is the one medication most people can safely take during a suspected heart attack. The 2025 guidelines from the American College of Cardiology and American Heart Association recommend chewing (not swallowing whole) a non-enteric-coated aspirin at a dose of 162 to 325 mg as soon as possible. Chewing gets the drug into your bloodstream faster, where it helps prevent the blood clot in your artery from growing larger.
Nitroglycerin, on the other hand, can be dangerous in certain situations. If you’ve taken medication for erectile dysfunction (such as sildenafil, tadalafil, or vardenafil) within the past 24 to 48 hours, combining it with nitroglycerin can cause a severe, potentially fatal drop in blood pressure. This combination is considered an absolute contraindication. Nitroglycerin can also be dangerous in certain types of heart attacks that affect the right side of the heart, where it can trigger cardiogenic shock. If nitroglycerin hasn’t been prescribed to you, don’t take someone else’s.
Don’t Try “Cough CPR”
A persistent myth circulating on social media claims that forceful, repeated coughing can keep your heart pumping during a heart attack. The American Heart Association has directly addressed this and says it does not work. The idea rests on a misunderstanding: coughing cannot restart a heart that has stopped, and during a heart attack (where the heart is still beating but starved of blood), coughing does nothing to improve blood flow to the damaged muscle.
There is a narrow, unrelated scenario where a doctor in a hospital might ask a patient to cough during a specific type of heart rhythm disturbance to maintain consciousness for a few seconds. But this is a supervised, temporary technique, not a self-treatment. As one cardiologist quoted by the AHA put it, “It physiologically does not make sense.” Attempting cough CPR wastes time you should be spending on the phone with 911.
Don’t Exert Yourself Physically
Walking around, climbing stairs, or trying to “push through” a suspected heart attack forces your heart to work harder at exactly the wrong moment. When you exercise or exert yourself, your heart demands more oxygen. During a heart attack, a blocked artery is already cutting off blood supply to part of the heart muscle. Increasing the heart’s oxygen demand while supply is restricted accelerates tissue death, particularly in the inner layers of the heart wall, which are the most vulnerable to reduced blood flow.
If you suspect a heart attack, sit or lie down immediately. If you’re alone, unlock your front door so paramedics can get in, then sit down and stay still. Reducing your body’s physical demands gives your heart the best chance of surviving until treatment arrives.
Don’t Ignore “Mild” Symptoms
Many people picture a heart attack as a dramatic, unmistakable event with severe chest pain and collapse. In reality, symptoms can be subtle, gradual, and easy to rationalize away. Jaw pain, upper back discomfort, nausea, unusual fatigue, and a cold sweat can all signal a heart attack without any chest pain at all. Women are particularly affected by this: they are significantly more likely than men to experience breathlessness, nausea, vomiting, dizziness, and back pain as their primary symptoms.
The danger of mild symptoms isn’t that they indicate a mild heart attack. The severity of symptoms doesn’t reliably correspond to the severity of the blockage. A heart attack that feels like bad indigestion can be just as deadly as one with crushing chest pain. If something feels wrong and you can’t explain it, especially if it comes with sweating, lightheadedness, or shortness of breath, call 911 immediately. The worst outcome of a false alarm is some embarrassment. The worst outcome of ignoring real symptoms is irreversible heart damage or death.