Mesenteric artery ischemia occurs when there is a narrowing or blockage of one or more of the three mesenteric arteries, the major arteries that supply the small and large intestines.

Narrowing of the arteries that supply blood to the intestine causes mesenteric ischemia. The arteries that supply blood to this area run directly from the aorta, the main artery from the heart.

Mesenteric artery ischemia is often seen in people who have hardening of the arteries in other parts of the body (for example, those with coronary artery disease or peripheral vascular disease). The condition is more common in smokers and in patients with high blood pressure or blood cholesterol.

Mesenteric ischemia may also be caused by a blood clot (embolus) that moves through the blood and suddenly blocks one of the mesenteric arteries. The clots usually come from the heart or the aorta. These clots are more commonly seen in patients with abnormal heart rhythms (arrhythmias), such as atrial fibrillation.