What Causes Coronary Microvascular Disease?

The same risk factors that cause atherosclerosis may cause coronary microvascular disease. Atherosclerosis is a disease in which plaque builds up inside the arteries.

Risk factors for atherosclerosis include:

• Diabetes. It is a disease in which the body’s blood sugar level is too high because the body doesn’t make enough insulin or doesn’t use its insulin properly.
• Family history of early heart disease. Your risk of atherosclerosis increases if your father or a brother was diagnosed with heart disease before age 55, or if your mother or a sister was diagnosed with heart disease before age 65.
• High blood pressure. Blood pressure is considered high if it stays at or above 140/90 mmHg over time. If you have diabetes or chronic kidney disease, high blood pressure is defined as 130/80 mmHg or higher. (The mmHg is millimeters of mercury—the units used to measure blood pressure.)
• Insulin resistance. This condition occurs if the body can’t use its insulin properly. Insulin is a hormone that helps move blood sugar into cells where it’s used for energy. Overtime, insulin resistance can lead to diabetes.
• Lack of physical activity. Physical inactivity can worsen some other risk factors for atherosclerosis, such as unhealthy blood cholesterol levels, high blood pressure, diabetes, and overweight or obesity.
• Older age. As you age, your risk for atherosclerosis increases. The process of atherosclerosis begins in youth and typically progresses over many decades before disease develops. 
• Overweight and obesity. The terms “overweight” and “obesity” refer to body weight that’s greater than what is considered healthy for a certain height.
• Smoking. Smoking can damage and tighten blood vessels, lead to unhealthy cholesterol levels, and raise blood pressure. Smoking also doesn’t allow enough oxygen to reach the body’s tissues.
• Unhealthy blood cholesterol levels. This includes high LDL (“bad”) cholesterol and low HDL (“good”) cholesterol.
• Unhealthy diet. An unhealthy diet can raise your risk for atherosclerosis. Foods that are high in saturated and trans fats, cholesterol, sodium (salt), and sugar can worsen other risk factors for atherosclerosis.

In women, coronary microvascular disease also may be linked to low estrogen levels occurring before or after menopause. Also, the disease may be linked to anemia or conditions that affect blood clotting. Anemia is thought to slow the growth of cells needed to repair damaged blood vessels.

Researchers continue to explore other possible causes of coronary microvascular disease.