This is a medical question of type : exams and tests 
 How to diagnose Atherosclerosis ? 
 Your doctor will diagnose atherosclerosis based on your medical and family histories, a physical exam, and test results.
                
Specialists Involved
                
If you have atherosclerosis, a primary care doctor, such as an internist or family practitioner, may handle your care. Your doctor may recommend other health care specialists if you need expert care, such as:
                
A cardiologist. This is a doctor who specializes in diagnosing and treating heart diseases and conditions. You may go to a cardiologist if you haveperipheral artery disease(P.A.D.)or coronary microvascular disease (MVD).
                
A vascular specialist. This is a doctor who specializes in diagnosing and treating blood vessel problems. You may go to a vascular specialist if you have P.A.D.
                
A neurologist. This is a doctor who specializes in diagnosing and treating nervous system disorders. You may see a neurologist if you've had a stroke due to carotid artery disease.
                
A nephrologist. This is a doctor who specializes in diagnosing and treating kidney diseases and conditions. You may go to a nephrologist if you have chronic kidney disease.
                
Physical Exam
                
During the physical exam, your doctor may listen to your arteries for an abnormal whooshing sound called a bruit (broo-E). Your doctor can hear a bruit when placing a stethoscope over an affected artery. A bruit may indicate poor blood flow due to plaque buildup.
                
Your doctor also may check to see whether any of your pulses (for example, in the leg or foot) are weak or absent. A weak or absent pulse can be a sign of a blocked artery.
                
Diagnostic Tests
                
Your doctor may recommend one or more tests to diagnose atherosclerosis. These tests also can help your doctor learn the extent of your disease and plan the best treatment.
                
Blood Tests
                
Blood tests check the levels of certain fats, cholesterol, sugar, and proteins in your blood. Abnormal levels may be a sign that you're at risk for atherosclerosis.
                
EKG (Electrocardiogram)
                
An EKG is a simple, painless test that detects and records the heart's electrical activity. The test shows how fast the heart is beating and its rhythm (steady or irregular). An EKG also records the strength and timing of electrical signals as they pass through the heart.
                
An EKG can show signs of heart damage caused by CHD. The test also can show signs of a previous or current heart attack.
                
Chest X Ray
                
A chest x ray takes pictures of the organs and structures inside your chest, such as your heart, lungs, and blood vessels. A chest x ray can reveal signs of heart failure.
                
Ankle/Brachial Index
                
This test compares the blood pressure in your ankle with the blood pressure in your arm to see how well your blood is flowing. This test can help diagnose P.A.D.
                
Echocardiography
                
Echocardiography (echo) uses sound waves to create a moving picture of your heart. The test provides information about the size and shape of your heart and how well your heart chambers and valves are working.
                
Echo also can identify areas of poor blood flow to the heart, areas of heart muscle that aren't contracting normally, and previous injury to the heart muscle caused by poor blood flow.
                
Computed Tomography Scan
                
A computed tomography (CT) scan creates computer-generated pictures of the heart, brain, or other areas of the body. The test can show hardening and narrowing of large arteries.
                
A cardiac CT scan also can show whether calcium has built up in the walls of the coronary (heart) arteries. This may be an early sign of CHD.
                
Stress Testing
                
During stress testing, you exercise to make your heart work hard and beat fast while heart tests are done. If you can't exercise, you may be given medicine to make your heart work hard and beat fast.
                
When your heart is working hard, it needs more blood and oxygen. Plaque-narrowed arteries can't supply enough oxygen-rich blood to meet your heart's needs.
                
A stress test can show possible signs and symptoms of CHD, such as:
                
Abnormal changes in your heart rate or blood pressure
                
Shortness of breath or chest pain
                
Abnormal changes in your heart rhythm or your heart's electrical activity
                
As part of some stress tests, pictures are taken of your heart while you exercise and while you rest. These imaging stress tests can show how well blood is flowing in various parts of your heart. They also can show how well your heart pumps blood when it beats.
                
Angiography
                
Angiography (an-jee-OG-ra-fee) is a test that uses dye and special x rays to show the inside of your arteries. This test can show whether plaque is blocking your arteries and how severe the blockage is.
                
A thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck. Dye that can be seen on an x-ray picture is injected through the catheter into the arteries. By looking at the x-ray picture, your doctor can see the flow of blood through your arteries.
                
Other Tests
                
Other tests are being studied to see whether they can give a better view of plaque buildup in the arteries. Examples of these tests include magnetic resonance imaging (MRI) and positron emission tomography (PET).