In healthcare, CAD most commonly stands for coronary artery disease, the single most common type of heart disease. It killed 371,506 people in the United States in 2022 alone, and roughly 1 in 20 American adults age 20 and older live with it. CAD is also sometimes short for computer-aided diagnosis, a technology used in medical imaging. This article covers both meanings, starting with the one you’re most likely looking for.
Coronary Artery Disease: The Basics
Coronary artery disease develops when the arteries supplying blood to your heart muscle gradually narrow and stiffen due to a process called atherosclerosis. It starts when the inner lining of an artery becomes damaged, often from high blood pressure, smoking, or high cholesterol. Once that lining is compromised, fatty deposits begin collecting beneath the surface. White blood cells rush in to clean up the fat but end up swollen with cholesterol themselves, forming what scientists call “foam cells.” Over time, smooth muscle cells, calcium, and fibrous tissue pile on top, creating a plaque that bulges inward and restricts blood flow.
A stable plaque develops a tough fibrous cap and may narrow the artery slowly over years. Symptoms typically appear once the artery is about 70% blocked, usually during physical activity when the heart needs more oxygen than the narrowed vessel can deliver. If the blockage reaches around 90%, chest pain can occur even at rest. The more dangerous scenario happens when a plaque ruptures suddenly, triggering a blood clot that can completely seal off the artery. That’s a heart attack.
Symptoms to Recognize
CAD is often called a “silent” disease because many people have no symptoms until a heart attack or other serious event. When symptoms do appear, the most common is angina: chest pain that feels like pressure, squeezing, tightness, or burning. This pain often shows up during physical activity or stress and fades with rest. It can also radiate to the shoulders, arms, neck, jaw, or back.
Other warning signs include shortness of breath (especially with activity), dizziness, lightheadedness, and unusual fatigue. Women are somewhat less likely than men to experience classic chest pain during a heart attack. Instead, they more often report extreme tiredness, nausea, stomach pain, or a vague pressure in the chest. Chest discomfort that doesn’t go away or occurs while you’re resting is a potential sign of a heart attack and needs emergency attention.
Major Risk Factors
About one in three adults has high blood pressure, the single largest contributor to CAD-related deaths. High blood pressure damages artery walls through both mechanical force and chemical stress, making them more vulnerable to plaque buildup. Only about 54% of people with hypertension have it adequately controlled.
High cholesterol is the second most significant risk factor. Globally, elevated cholesterol contributes to an estimated 2.6 million deaths per year. When LDL cholesterol (the “bad” kind) is high, more of it gets deposited in artery walls, accelerating plaque formation.
Smoking roughly doubles the risk of cardiovascular disease for current smokers and raises it by 37% even in former smokers over age 60. Even nonsmokers regularly exposed to secondhand smoke face a 25% to 30% higher risk. Diabetes, obesity, a sedentary lifestyle, poor diet, and chronic stress round out the list of modifiable risk factors.
How CAD Is Treated
Treatment depends on how far the disease has progressed. For many people, the first line of defense is medication combined with lifestyle changes. Statins help control cholesterol and slow plaque growth. Blood pressure medications, including ACE inhibitors and beta blockers, reduce the workload on the heart. Low-dose aspirin (75 to 100 milligrams daily) acts as a blood thinner to prevent clots, and nitroglycerin can relieve or prevent angina episodes.
When arteries are severely narrowed, procedures may be necessary. Angioplasty (also called percutaneous coronary intervention) involves threading a small balloon into the blocked artery to widen it, often with a mesh tube called a stent left in place to keep it open. For people with blockages in multiple arteries, coronary artery bypass grafting uses healthy blood vessels from the chest wall or legs to reroute blood flow around the damaged sections. Weight loss surgery is sometimes recommended for people with obesity and CAD, particularly if they also have diabetes, because it can substantially lower cardiovascular risk.
Preventing Coronary Artery Disease
The most effective prevention targets the same risk factors that cause the disease. For exercise, the general recommendation is at least 150 minutes per week of moderate activity like brisk walking, or 75 minutes of vigorous activity like running, plus two or more strength training sessions. If you’ve been inactive, working up to these targets gradually is fine.
Diet matters just as much. Heart-healthy eating patterns like the Mediterranean diet and the DASH plan emphasize vegetables, fruits, legumes, whole grains, lean protein, fish, and healthy fats like olive oil and avocado while limiting processed foods, added sugars, and excess sodium. These patterns lower blood pressure, improve cholesterol, and reduce inflammation in artery walls. Not smoking, or quitting if you do, remains one of the single most impactful changes you can make for your heart.
The Other CAD: Computer-Aided Diagnosis
In radiology and medical imaging, CAD refers to computer-aided diagnosis, software that analyzes medical images like mammograms, CT scans, and X-rays to flag areas that may indicate disease. The system acts as a “second opinion” for the radiologist, who still makes the final call. CAD is designed to complement human judgment, not replace it. The goal is a synergistic effect: the computer catches patterns the human eye might miss, while the physician applies clinical context the software can’t.
The technology’s track record is mixed. A large study published in the New England Journal of Medicine examined CAD’s impact on mammography screening and found that while sensitivity increased slightly (from 80.4% to 84.0%), the change was not statistically significant. More concerning, specificity dropped from 90.2% to 87.2%, meaning more false alarms. Overall diagnostic accuracy actually decreased with CAD use. Still, the technology continues to evolve, particularly with the integration of artificial intelligence, and remains widely used in breast cancer screening and lung nodule detection.