Coronary artery disease (CAD) occurs when the arteries that supply blood to the heart become hardened and narrowed due to the buildup of cholesterol and other substances, known as plaque. As plaque builds up and the blockage grows, the heart cannot get the blood or oxygen it needs to function. CAD is the most common type of heart disease and the leading cause of death for both men and women in the United States. The disease kills more than 370,000 Americans each year, according to the Centers for Disease Control and Prevention (CDC). Signs and symptoms of CAD include:

Chest pain (angina)Shortness of breathHeart attack

Physical or emotional stress may trigger pressure or tightness in your chest, as if a large weight is resting on it. This pain is called angina, and it can be a sign of CAD. Chest pain that occurs with exertion and is relieved with rest, or the medication nitroglycerin, is also typical of angina. If you experience shortness of breath or extreme fatigue following exercise or physical stress, this could also be a sign of a blockage in the arteries leading to your heart. Finally, a blocked coronary artery can cause a heart attack. You may feel pain in your left shoulder or arm, or intense pressure on your chest. If you suspect you are having a heart attack, seek emergency assistance immediately. If you have any other symptoms of CAD, talk to your doctor. If your doctor thinks you may have CAD or are at high risk for the disease, he or she may recommend the following tests:

An electrocardiogram (ECG or EKG) to see if you’ve had a heart attackAn echocardiogram to assess heart functionA stress test to gather information about your heart during physical activityA cardiac catheterization or angiogram to check blood flow through your heartA computerized tomography (CT) scan of your heart to check for calcium deposits in your arteriesMagnetic resonance angiography (MRA), using MRI technology, to look for blockages

For a stress test, your doctor may ask you to walk on a treadmill or ride a stationary bike while monitoring your heart by ECG. Sometimes your doctor may use medication to elevate your heart rate.

CAD Causes and Risk Factors

Damage to the inner wall of the coronary arteries, leading to plaque buildup, can begin as early as childhood. This damage may be the result of:

SmokingHigh blood pressureHigh cholesterolDiabetesRadiation therapy for cancer (in chest area)Inactive lifestyleFamily history of CADOverweight and obesityHigh levels of stress

In addition to these risk factors, simply getting older increases your risk for CAD. Men are also more likely than women to develop CAD. Researchers are also studying other factors that may lead to CAD, including sleep apnea as well as:

Elevated C-reactive proteinElevated triglyceridesElevated homocysteineElevated lipoprotein-a

Elevated levels of these substances will show up in blood tests. If any risk factors for CAD apply to you — such as smoking or having high blood pressure — talk to your doctor. Even if you don’t have any signs or symptoms of CAD, your doctor may want to treat you for conditions such as high blood pressure or high cholesterol to help reduce your future risk.

CAD Treatment

If you receive a diagnosis of CAD, your doctor may recommend the following lifestyle changes:

Quitting smokingEating healthier foodsExercising regularlyLosing weightReducing stress

In addition, a number of prescription drugs are used to treat CAD, including:

Cholesterol-lowering drugs, designed to reduce LDL (low-density lipoprotein, or “bad”) cholesterol levelsAspirin or another blood thinner to reduce your risk of blood clotsBeta blockers to lower your heart rate and blood pressureNitroglycerin to control chest pain by clearing blockages in your coronary arteries and reducing your heart’s demand for bloodAngiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) to lower your blood pressure

Finally, in some cases CAD may require more aggressive treatment in the form of stents (small pieces of metal) placed in your coronary arteries, angioplasty, or coronary artery bypass surgery. In coronary artery stent placement, a cardiologist inserts a long, thin tube (catheter) into the narrowed coronary artery, then places a small metal stent inside the artery. The stent expands the walls of the artery to prop it open and improve coronary blood flow. In angioplasty, a cardiologist inserts a catheter into the narrowed part of your artery to place a deflated balloon. The surgeon then inflates the balloon to compress any deposits against your artery walls. In coronary artery bypass surgery, a surgeon creates a graft to bypass blocked coronary arteries using a blood vessel from another part of your body. This requires open heart surgery.

CAD Complications

Coronary artery disease can cause the following complications:

AnginaHeart attackInability of the heart to pump enough blood (heart failure)Abnormal heart rhythm (arrhythmia)

Early diagnosis and treatment of CAD may stop or slow its progression and help prevent many of these complications.