What causes Coronary Heart Disease ?
Research suggests that coronary heart disease (CHD) starts when certain factors damage the inner layers of the coronary arteries. These factors include:
                
Smoking
                
High levels of certain fats and cholesterol in the blood
                
High blood pressure
                
High levels of sugar in the blood due to insulin resistance or diabetes
                
Blood vessel inflammation
                
Plaque might begin to build up where the arteries are damaged. The buildup of plaque in the coronary arteries may start in childhood.
                
Over time, plaque can harden or rupture (break open). Hardened plaque narrows the coronary arteries and reduces the flow of oxygen-rich blood to the heart. This can cause angina (chest pain or discomfort).
                
If the plaque ruptures, blood cell fragments called platelets (PLATE-lets) stick to the site of the injury. They may clump together to form blood clots.
                
Blood clots can further narrow the coronary arteries and worsen angina. If a clot becomes large enough, it can mostly or completely block a coronary artery and cause a heart attack.