The term heart diseases is used to denote any of the various diseases and health problems that may affect the heart, such as vascular diseases such as coronary artery disease , heart rhythm disorders , and congenital heart defects. The term cardiovascular disease is used instead of the term heart disease to describe diseases that affect blood vessels, such as narrowing of blood vessels, which may result in a heart attack., Or chest angina, or stroke, and other health problems that affect the heart as well, and according to the Centers for Disease Control and Prevention, heart disease is the main cause of death in many developed countries, where it is estimated that the death rate from heart disease in the United States is 25. % Of all deaths, and it is worth noting that most heart diseases can be prevented or treated through a healthy lifestyle.  
Diagnose heart disease
Clinical examination and blood tests
At the beginning of the diagnosis of heart disease, the doctor asks the patient about the health history of him and his family, evaluates the symptoms and signs associated with the disease, and measures blood pressure and heart rate of the patient, and the doctor may request some blood tests, such as the CRP-C to detect the presence of inflammation in a part of the body, and analyzes to measure the proportion of cholesterol and fats in the blood, and these tests are done to detect the risk of developing a heart disease, or the risk of a heart attack, and the comprehensive cholesterol test to detect There are four different types of fats in the blood, as follows: 
- Total: cholesterol , which is a total percentage of the different types of cholesterol in the blood.
- High - density lipoprotein: and Acronym HDL, and called the term good cholesterol, which is responsible for removing fat from the arteries protein.
- Low - density lipoprotein: and Acronym LDL, and called the term bad cholesterol, which leads the presence of large amounts of this protein in the blood to the accumulation of fat within the walls of the arteries , which affects blood flow in the body, and may result in Having a stroke , or a heart attack.
- Triglycerides: In most cases, high levels of triglycerides in the blood are associated with smoking, drinking alcoholic beverages, and developing diabetes.
Noninvasive diagnostic tests
After the completion of the clinical examination and blood tests, the doctor may perform some non-invasive diagnostic tests to help diagnose the condition more clearly, which are diagnostic tests that do not include the introduction of any tools or devices through the skin or inside the human body, and the following is a statement of some These tests are:  
- Cardiac CT scan: The principle of this test is based on the use of x-rays to take many pictures of the chest and heart region, by lying down the patient inside a dedicated machine, containing an X-ray machine installed on a tube that can be rotated to obtain a cross-sectional image of the heart, to help diagnose diseases Different heart.
- Cardiac magnetic resonance imaging: In this test, radio waves and large magnetic waves are used to obtain multiple images of the heart, and through this test, it can detect many heart diseases, such as coronary artery disease, and diseases that affect the heart muscle .
- Electrocardiogram: , short for ECG, and this test is based on measuring the electrical activity of the heart. The test revealed a structural problem with the heart or an abnormal heart rhythm.
- Device Holter: This device is used in the event of an inability to detect health problem by using the method of electrical planning the usual heart, a Holter is a mobile device that is used to monitor the electrical activity of the patient 's heart for a period of 24-72 hours continuously.
- Echo Heart: Planning This test on imaging the heart using ultrasound, and in which you can get pictures minutes of the heart, this helps test to detect the presence of health problems in one of the heart muscles, or in one of the heart valves .
- Table Test Inclined: is used for this test if the patient is exposed to fainting earlier, where the patient is asked to lie down on a dedicated table, this is then move the table horizontally and vertically and monitor heart rate, blood pressure, and the concentration of oxygen In the blood, and this test helps to reveal the cause of fainting, and whether it is related to heart disease.
Invasive diagnostic tests
The doctor may need to resort to some invasive diagnostic tests in some cases, which include the use of some devices that require the insertion of some tools into the body, such as a catheter, needle, or specific tube. Among these tests we mention the following:  [4 ]
- Electrophysiology study test: This study is carried out in some cases of arrhythmia, where a catheter containing an electrode is inserted into the heart through a blood vessel , through which some electrical signals are sent to the heart, and the electrical activity is recorded To the heart.
- Cardiac catheterization: In this case, a long, flexible tube is inserted through one of the veins or arteries in the arm, or at the origin of the thigh, and is guided using x-rays to the heart, and through this method, pressure can be measured in the various heart chambers. An injection of a special dye that can be detected using x-rays can also be done to reveal the pattern of blood flow through the heart .
- "Heart disease" , www.mayoclinic.org , 22-3-2018, Retrieved 4-7-2018. Edited.
- Adam Felman (7-2-2018), "Everything you need to know about heart disease" , www.medicalnewstoday.com , Retrieved 4-7-2018. Edited.
- Valencia 's Higuera, "How To Is Heart View Disease Diagnosed?" , Www.healthline.com , Retrieved 4-7-2018. Edited.
- "Heart View & DISEASE Diagnosis Treatment" , Www.mayoclinic.org , 22-3-2018, Retrieved 4-7-2018. Edited.