Atherosclerosis is a slow disease in which your arteries become clogged and hardened. It is the underlying cause of most cases of heart attack, stroke, and vascular dementia, and is found in 80 to 90% of Americans over the age of 30. Fat, cholesterol, calcium, and other substances form plaque, which builds up in arteries. Hard plaque narrows the passage that blood flows through. That causes arteries to become stiff and inflexible (atherosclerosis is also known as hardening of the arteries). It contributes to the development of cardiovascular disease, which is the leading cause of death in people over 45. Soft plaque is more likely to break free from the artery wall and cause a blood clot, which can block blood flow to vital organs.
The effects of atherosclerosis differ depending upon which arteries in the body narrow and become clogged with plaque. If the arteries that bring oxygen-rich blood to your heart are affected, you may have coronary artery disease, chest pain, or a heart attack. If the arteries to your brain are affected, you may have a transient ischemic attack (TIA) or a stroke. If the arteries in your arms or legs are affected, you may develop peripheral artery disease. You may also develop a bulge in the artery wall (aneurysm).
Lowering blood pressure and LDL ("bad") cholesterol levels, eating a healthy diet with lots of fruits and vegetables, quitting smoking, losing weight, and getting more exercise can prevent atherosclerosis.
Signs and Symptoms
Many times, people with atherosclerosis do not have any symptoms until an artery is 40% clogged with plaque. Symptoms vary depending upon which arteries are affected.
Coronary Artery Disease
Symptoms of coronary artery disease (where the heart arteries narrow) are usually brought on by physical exercise, sexual activity, exposure to cold weather, anger, or stress. Common symptoms include:
- Chest pain (generally a heavy, squeezing, or crushing sensation with possible burning or stabbing pains)
- Abdominal, neck, back, jaw, or shoulder/arm pain
- Shortness of breath
Cerebrovascular disease (where the arteries that supply the brain with blood are narrowed) can cause transient ischemic attack (a sudden loss of brain function with complete recovery within 24 hours) and stroke. Symptoms may include:
- Weakness or paralysis on one side of the body
- Trouble speaking or understanding speech
- Loss of vision in one eye
- Muscle weakness
- Sudden trouble walking
- Loss of balance or coordination
- Sudden severe headache
Peripheral Artery Disease
Peripheral artery disease affects the arteries that supply the arms and legs with oxygen-rich blood. Symptoms may include:
- Pain, aching, cramps, numbness, or sense of fatigue in the leg muscles (intermittent claudication)
- "Bruits" (blowing sounds your doctor can hear with a stethoscope that indicate turbulence in blood flow)
- Hair loss
- Thickened nails
- Smooth, shiny skin surface
- Skin that is cold to the touch
What Causes It?
No one knows the exact cause of atherosclerosis, although they do know what causes it to get worse. Many researchers believe it begins with an injury to the innermost layer of the artery, known as the endothelium. Researchers believe the following factors contribute to the damage:
- High blood pressure
- Elevated LDL ("bad") cholesterol
- An accumulation of homocysteine. An amino acid produced by the human body, thought to be a risk factor for heart disease, stroke, osteoporosis, diabetes, and dementia.
- Overweight or obesity
- Unhealthy diet
- Lack of exercise
- Family history of heart disease
Once the artery is damaged, blood cells called platelets build up there to try and heal the injury. Over time, fats, cholesterol, and other substances also build up at the site, which thickens and hardens the artery wall. The blood flow through the artery is decreased, and the oxygen supply to organs also decreases. Blood clots may form, blocking the artery and cutting off blood supply to other organs.
Some people do not have the classic risk factors of atherosclerosis (such as cigarette smoking and high blood pressure). It is possible that there may be other causes, such as an infection. Research is ongoing.