Inflammation is common in patients with heart disease and those who have experienced a stroke and is thought to be a sign or response to fatty deposits. It’s important to know what inflammation is and what it can do to your heart.

In terms that we more easily understand, a splinter in your finger will cause the white blood cells and other agents in your blood to attack the damaged area to kill any bacteria and rid your body of the intruder. This causes redness and swelling.

Similarly, for the cardiovascular system, risk factors like cigarette smokinghigh blood pressure, and LDL (bad) cholesterol can “injure” the heart. In turn, the buildup of fatty deposits in the inner walls of the heart’s arteries can develop. This narrows the arteries and increases the risk they’ll become blocked.

“Exactly how inflammation plays a role in heart attack and stroke remains a topic of ongoing research,” says Deepak Bhatt, M.D., associate professor of medicine at Harvard Medical School. “It appears that the inciting event in many heart attacks and some forms of stroke is the buildup of fatty, cholesterol-rich plaque in blood vessels.”

“The body perceives this plaque as abnormal and foreign, it does not belong in a healthy blood vessel,” he said. “In response, the body tries to wall off the plaque from the flowing blood. However, under the wrong set of circumstances, that plaque may rupture, and its walled-off contents can come into contact with blood and trigger a blood clot formation.”

Bhatt added, “This combination of plaque and blood clots causes the majority of heart attacks and certain types of stroke if the blood clot obstructs blood flow to the heart or brain.”

An artery to the heart that’s blocked causes a heart attack. A blocked artery in or leading to the brain causes a stroke.