Checking for heart disease typically starts with simple, noninvasive tests and works up to more detailed imaging or procedures based on your symptoms and risk factors. Most people begin with blood work, an electrocardiogram, and a conversation with their doctor about family history and lifestyle. From there, the specific tests you need depend on what your doctor suspects and what the initial results show.
Blood Tests: The First Line of Screening
Blood tests are usually the starting point because they’re cheap, fast, and reveal a lot. A standard lipid panel measures your cholesterol and triglycerides, which are the fatty substances that build up inside artery walls over time. High levels of LDL cholesterol (the “bad” kind) are one of the strongest predictors of future heart problems.
Blood sugar levels matter too. Elevated fasting glucose or a high A1C reading signals diabetes or prediabetes, both of which significantly increase cardiovascular risk. Your doctor may also check C-reactive protein, a marker of inflammation in the arteries that can signal developing disease even when cholesterol looks normal.
If a heart attack is suspected, the key blood test looks for troponin, a protein that leaks into the bloodstream when heart muscle is damaged from lack of oxygen. Normal troponin I levels are typically less than 0.12 ng/mL, and troponin T levels are usually below 0.01 ng/mL. Elevated troponin is the most reliable biomarker for confirming a heart attack, per American Heart Association guidelines.
One newer screening recommendation: the 2026 ACC/AHA guidelines now recommend that all adults have their lipoprotein(a) measured at least once in their lifetime. Lipoprotein(a) is a genetically determined type of cholesterol particle that raises heart disease risk independently of your regular cholesterol numbers. You can’t lower it with diet or exercise, but knowing your level helps your doctor assess your overall risk more accurately.
EKG: Reading Your Heart’s Electrical Signals
An electrocardiogram (EKG or ECG) is a quick, painless test that records the electrical signals controlling your heartbeat. Small adhesive patches are placed on your chest, arms, and legs, and the test takes just a few minutes. It can show whether your heart is beating too fast, too slow, or irregularly, and it picks up signs of a previous heart attack by identifying areas of damaged tissue that conduct electricity differently.
A standard EKG captures only a brief snapshot. If your symptoms come and go (dizzy spells, palpitations, fainting), your doctor may have you wear a Holter monitor, which is a portable EKG device you carry for 24 hours or longer. It records your heart’s activity continuously during normal daily life and catches irregular rhythms that a short office EKG would miss.
Echocardiogram: Seeing the Heart’s Structure
While an EKG measures electrical activity, an echocardiogram uses ultrasound waves to create a moving picture of your heart’s physical structure. It shows the size of each chamber, how well the left ventricle (the main pumping chamber) is working, and whether blood is flowing correctly through the valves. If a valve is narrowed, leaking, or if the heart muscle has thickened or weakened, the echo reveals it.
This distinction matters. You can have a perfectly normal EKG and still have structural heart disease, like a failing valve or a weakened heart muscle. The two tests answer fundamentally different questions: the EKG asks “Is the electrical system working?” and the echo asks “Is the physical structure intact?”
Stress Tests: How Your Heart Handles Exertion
Some heart problems only show up when your heart is working hard. A stress test monitors your heart while you walk on a treadmill or ride a stationary bike, gradually increasing the intensity. Your doctor watches for changes in your EKG, drops in blood pressure, or symptoms like chest pain or shortness of breath that appear only under exertion. If you can’t exercise due to joint problems or other limitations, you’ll be given a medication that mimics the effect of exercise on your heart.
Preparing for a stress test requires some planning. You’ll need to avoid caffeine for 24 hours beforehand, including coffee, tea, energy drinks, and certain over-the-counter medications that contain it. You shouldn’t eat in the hours leading up to the test, and you’ll need to skip tobacco products that day. Some prescription medications, particularly beta-blockers and asthma inhalers, may need to be paused on test day. If you take diabetes medications, coordinate with your doctor ahead of time so you can manage your blood sugar safely around the fasting requirement.
Coronary Calcium Scan: Measuring Plaque Buildup
A coronary calcium scan is a specialized CT scan that detects calcium deposits in the walls of your heart’s arteries. Calcium accumulates inside arterial plaque, so the amount of calcium correlates with how much plaque has built up. The result is expressed as an Agatston score.
Here’s how the numbers break down:
- Score of 0: No calcium detected. This suggests a low chance of heart attack in the coming years.
- Score of 1 to 99: Mild plaque deposits. Some disease is present, but risk remains relatively low.
- Score of 100 to 300: Moderate plaque. This carries a relatively high risk of heart attack or other heart disease over the next three to five years.
- Score above 300: Extensive plaque deposits and a significantly higher heart attack risk.
This test is most useful for people in a gray zone of risk, where traditional factors like cholesterol and blood pressure don’t clearly point toward or away from treatment. A zero score can be reassuring enough to hold off on medication, while a high score often tips the decision toward more aggressive prevention. The scan itself takes only a few minutes and doesn’t require any dye or needles.
Cardiac Catheterization: The Definitive Look
When noninvasive tests point toward blocked arteries but can’t confirm the exact location or severity, cardiac catheterization provides the definitive answer. A thin, flexible tube is threaded through a blood vessel in your wrist or groin and guided to the heart, where dye is injected so the arteries show up clearly on X-ray. This reveals the precise location and degree of any blockages.
The procedure itself typically takes about 30 minutes if the goal is purely diagnostic, but the full appointment, including prep and recovery, runs five to nine hours or longer. If the catheter goes through your arm, you’ll need to keep your arm straight for at least an hour and stay under observation for a few hours. If it goes through the groin, expect to lie flat with your leg straight for two to six hours to prevent bleeding at the insertion site. Catheterization is invasive and carries small risks, so it’s reserved for situations where less invasive tests have already suggested significant disease.
Cardiac MRI and Chest X-Ray
A cardiac MRI uses powerful magnets and radio waves to create highly detailed images of the heart’s structure and surrounding tissue. It’s particularly useful for evaluating heart muscle damage, tumors, or complex congenital heart problems that an echocardiogram can’t fully characterize. It’s not a first-line screening tool, but when your doctor needs the most precise structural image possible, MRI delivers it.
A chest X-ray, on the other hand, is far simpler. It can show whether the heart is enlarged and reveal fluid in the lungs, both signs of heart failure. It’s often done as part of a general workup rather than as a standalone heart disease test.
Smartwatches and Wearable Monitors
Consumer smartwatches have become surprisingly accurate at detecting atrial fibrillation, the most common dangerous heart rhythm disorder. A 2025 meta-analysis of 26 studies covering over 17,000 patients found that smartwatches overall detected atrial fibrillation with 95% sensitivity and 97% specificity. Apple Watch achieved 94% sensitivity and 97% specificity, while Samsung devices hit 97% sensitivity and 96% specificity.
These numbers are impressive for a consumer device, but they come with an important caveat. Smartwatches are screening tools, not diagnostic ones. A notification from your watch doesn’t confirm a diagnosis. It does, however, give you a concrete reason to get a proper EKG, which can make all the difference for people who might otherwise ignore occasional palpitations or lightheadedness.
Symptoms That Look Different in Women
Women are much more likely than men to experience atypical heart disease symptoms, which can delay testing and diagnosis. While chest pain is still the most common heart attack symptom across both sexes, women more frequently report indigestion, shortness of breath, back pain, nausea, and abdominal discomfort, sometimes without any obvious chest pain at all. These symptoms are easy to attribute to stress, acid reflux, or fatigue, which is part of why heart disease in women is underdiagnosed. If you’re a woman experiencing persistent, unexplained symptoms like these, especially with risk factors like high blood pressure, diabetes, or a family history of heart disease, pushing for cardiac testing is reasonable.