Atherosclerosis is dangerous because it's so stealthy. This process of narrowing and hardening of the arteries occurs over decades, usually without any symptoms.
Heart attacks and strokes caused by atherosclerosis are responsible for hundreds of thousands of deaths each year. But diseases caused by atherosclerosis also lead to chronic pain, kidney failure, blindness, and even impotence.
It's time to shine some light on these hidden complications of atherosclerosis -- and to learn how to prevent them.
Diseases Caused by Atherosclerosis: A Hidden Enemy
Out of sight, often out of mind, atherosclerosis does its slow, dirty work on our arteries. How does it happen?
Low-density lipoprotein (LDL or "bad" cholesterol) damages arteries, building up in their walls. Over years, the body's response to the fatty deposits creates a plaque, or a bump in the artery wall.
"Over years, these atherosclerotic plaques can grow until they significantly hinder blood delivery to the tissues," says Mark Silverman, MD, emeritus professor of medicine at Emory University.
"Alternately, a plaque can suddenly rupture," causing a blood clot to form, blocking off the artery completely. "Within hours, the tissue that depends on the artery for blood dies," says Silverman.
High blood pressure, diabetes, obesity, smoking, and a high-fat diet low in fruits and vegetables all tend to make atherosclerosis worse.
Plaques grow slowly and blood flow is preserved for years, so atherosclerosis causes no early symptoms. "When symptoms finally do occur, the blockages are severe and usually irreversible," explains Silverman.
Diseases Caused by Atherosclerosis: Beyond the Heart
The entire body is dependent on arteries for oxygenated blood. "Because arteries everywhere can be affected, there is no organ system atherosclerosis can't reach," says Lori Mosca, MD, MPH, PhD, director of preventive cardiology at New York-Presbyterian Hospital. "And atherosclerosis, when present, is usually widespread."
Take this short trip through the arteries of the body to consider the less well-known complications of atherosclerosis.
Your Kidneys
Arteries carry blood to the kidneys, where our entire blood volume is filtered more than 30 times a day. If atherosclerosis slows the flow, chronic kidney disease can result. This can eventually lead to end-stage renal disease, or total kidney failure requiring dialysis.
Blockages to both kidneys' arteries can also cause blood pressure to go sky-high, in a condition called renal artery stenosis.
"Atherosclerosis in the renal arteries can be important and is most likely underdiagnosed," says Silverman. "When these vessels are also pounded by high blood pressure, the effects of atherosclerosis are compounded."
Your Eyes
Tiny arteries carry blood to the nerves of the eye. If an atherosclerotic plaque breaks off and blocks the central retinal artery, an "eye stroke" results, causing blindness in one eye.
Your Sex Organs
Men need strong blood flow into the penis to get and maintain firm erections. Arteries in the penis can get damaged by atherosclerosis, too, and can't deliver the necessary blood flow. Erectile dysfunction can result.
It's a common problem: up to 39% of 40-year-old men report some degree of erectile dysfunction, and two-thirds of men over 70 have significant symptoms. Atherosclerosis is the most common cause of erectile dysfunction.
Your Digestive System
Atherosclerosis can narrow the arteries that supply blood to the intestines. The result can be mesenteric ischemia: belly pain after eating, when the body tries to ramp up blood supply to the gut, but can't.
"Mesenteric ischemia is actually quite uncommon, although it can occasionally be mistaken for indigestion," according to Silverman.
Your Aorta
The aorta is the main pipeline of blood from the heart to the body. A swollen, weak patch of this muscular artery is called an aortic aneurysm. These aneurysms frequently form in the abdominal aorta. Atherosclerosis is often present in these dangerous outpouchings, which can rupture and cause life-threatening bleeding.
Of course, there are also the "big three" complications of atherosclerosis, caused by blockages in the heart, brain, or legs:
- Coronary artery disease (heart)
- Stroke (brain)
- Peripheral arterial disease (legs)
Together, these diseases are responsible for the vast majority of atherosclerosis complications.
Your Heart
The coronary arteries run along the surface of the heart, delivering vital blood flow. Atherosclerotic plaques can slowly choke them off, resulting in coronary artery disease.
The most common symptom of coronary artery disease? According to Silverman, it's having no symptoms at all. Some people will experience angina (chest discomfort, often with exertion).
Angina can be stable, meaning symptoms progress slowly or not at all, and don't permanently damage heart muscle.
If a plaque gets disrupted, unstable anginacan result. In unstable angina, chest discomfort changes, becomes more severe, or occurs at rest. "Usually, this means there is inflammation in the plaque," which is now highly dangerous, says Silverman.
Unstable angina can quickly transform into a blood clot, blocking a coronary artery. This causes a heart attack, or myocardial infarction. Heart muscle, starved for blood, dies.
Heart attacks also frequently occur with no prior symptoms of angina. "The initial symptom of a heart attack in 50% of men is sudden death," warns Silverman.
Heart attacks or severe blockages can also cause heart failure. "The heart doesn't really fail, but can't pump blood well enough to keep up with demand," says Mosca. The result can be shortness of breath with activity, or leg swelling. Heart failure is a serious problem, and atherosclerosis is one of the most common causes.
Your Brain
Our brains demand an enormous amount of energy, delivered by blood through a handful of arteries in our necks and heads. A stroke happens when a vital artery delivering blood to the brain becomes blocked. If the artery is not reopened quickly, the brain tissue it supplies dies. Permanent brain damage can result in lasting weakness or difficulty with speech.
In a transient ischemic attack (TIA), stroke symptoms occur, but then resolve. Most likely, TIAs are caused by blockages that somehow improve spontaneously. TIAs are near-misses, warning that a real stroke could occur at any time.
Half of all strokes are caused by atherosclerosis. Similar to a heart attack, a stroke is a "brain attack." An unstable atherosclerotic plaque ruptures, a blood clot forms, and the artery is blocked. Less commonly, a plaque elsewhere breaks off and travels up an artery into the brain.
Your Legs and Feet
Progressive narrowing of the arteries of the legs leads to peripheral arterial disease. Symptoms are in the muscle groups of the leg (buttock, thigh, or calf) and most often occur with exercise, disappearing with rest. They can occur on one side or both.
"Although some people are incapacitated by the chronic pain caused by peripheral arterial disease, this is rare," says Silverman. "Many people have no symptoms at all, even with significant disease," he adds.
Diseases Caused by Atherosclerosis: Treatment Is All for One, One for All
Atherosclerosis is a many-headed hydra, causing many complications through a single disease process. "If you have any manifestation of atherosclerosis, you are at risk of having the others," emphasizes Mosca.
"The good news is, treating your risk factors for atherosclerosis reduces the risk for all these complications at once," says Silverman.
What can you do?
- Get your cholesterol and blood pressure checked and treated if high.
- Exercise several days of the week.
- Don't smoke.
- Eat a diet with lots of fruits and vegetables and low in saturated fat.
Around 90% of the risk of a first heart attack is avoidable by following this plan. And because diseases caused by atherosclerosis are interrelated, says Silverman, "changing these behaviors reduces the risk for the other complications of atherosclerosis as well."
