The most common cause of MI is coronary artery disease (CAD), where the coronary arteries (which supply blood to the heart) become narrowed or blocked due to the buildup of a waxy substance called plaque. This process is known as atherosclerosis.

• Atherosclerosis: The gradual buildup of plaque in the arteries, leading to narrowing and hardening. This is the primary underlying cause.
• Blood Clot Formation: When a plaque in a coronary artery ruptures, a blood clot often forms on its surface. If this clot becomes large enough, it can completely block blood flow to that part of the heart muscle, leading to a heart attack.
• Coronary Artery Spasm: In some cases, a heart attack can be caused by a sudden, severe spasm of a coronary artery, temporarily constricting blood flow. This can occur even in arteries without significant plaque buildup.
• Other Less Common Causes: Trauma to the chest, certain electrolyte imbalances, eating disorders, or rare congenital heart defects can also lead to MI.

Risk Factors for Myocardial Infarction

• High Blood Pressure (Hypertension): Increases the workload on the heart, leading to thickening and stiffening of the heart muscle.
• High Blood Cholesterol (Dyslipidemia): High levels of LDL (“bad”) cholesterol and triglycerides, and low levels of HDL (“good”) cholesterol contribute to plaque formation.
• Diabetes Mellitus: High blood sugar levels damage blood vessels over time, increasing the risk of atherosclerosis.
• Smoking/Tobacco Use: Damages blood vessels, increases blood pressure, and makes blood more prone to clotting. Even exposure to secondhand smoke increases risk.
• Obesity/Overweight: Often linked to other risk factors like high blood pressure, high cholesterol, and diabetes.
• Physical Inactivity: Lack of exercise contributes to obesity, high blood pressure, and high cholesterol.
• Unhealthy Diet: Diets high in saturated and trans fats, sodium, and refined sugars promote atherosclerosis.
• Stress: Chronic stress can contribute to various risk factors and directly impact heart health.
• Excessive Alcohol Consumption: Can contribute to high blood pressure and other heart problems.

Non-Modifiable Risk Factors-

• Age: The risk of heart attack generally increases with age. For men, the risk typically rises after age 45, and for women, after age 50 or post-menopause.
• Sex: Men generally have a higher risk earlier in life, but women’s risk increases after menopause and can become similar to men.
• Family History: A strong family history of early heart disease (e.g., father or brother diagnosed before age 55; mother or sister before age 65) increases individual risk due to genetic predispositions.