Atherosclerosis can take decades to develop, but research shows it can accelerate rapidly, especially during your 40s and 50s. Plaque buildup in the arteries often begins silently in the teenage years, long before any symptoms appear. By the time most people are aware they have a problem, the disease may have been progressing quietly for years.
Peripheral artery disease (PAD) is a condition in which narrowed arteries reduce blood flow to the limbs, most often due to atherosclerosis (plaque buildup in the arteries). Understanding this connection can help you recognize warning signs earlier and protect your vascular health, especially if you have risk factors such as high cholesterol, smoking, diabetes, or a family history of vascular disease. More on PAD and when a vascular evaluation may be worth considering throughout this article.
What Is Atherosclerosis and Why Does It Progress?
Atherosclerosis is a condition in which fatty deposits, cholesterol, calcium, and other substances accumulate inside the walls of the arteries, forming what is known as plaque. Over time, this plaque hardens and narrows the arteries, reducing blood flow throughout the body.
The process is not a single event. It is a slow-building, chronic condition influenced by ongoing injury and inflammation in the artery walls. Once the first signs of damage appear, the buildup tends to continue unless something interrupts it.
How Plaque Forms in the Arteries
Plaque development begins when the inner lining of an artery, called the endothelium, becomes damaged. This damage can result from high blood pressure creating repeated stress on the artery walls, elevated LDL cholesterol circulating in the bloodstream, tobacco smoke chemicals injuring the vessel lining, or elevated blood sugar from diabetes. Once the lining is compromised, low-density lipoprotein (LDL) cholesterol particles can enter and accumulate in the artery wall.
White blood cells arrive to address the inflammation and absorb the cholesterol, but instead of clearing it, they transform into foam cells that become trapped in the artery wall. These foam cells accumulate, and over time, the buildup grows into what becomes recognizable as arterial plaque.[1]
Why the Process Is Often Silent
One of the most concerning aspects of atherosclerosis is that the early stages rarely cause noticeable symptoms. Arteries are flexible enough that even moderate plaque buildup may not restrict blood flow significantly. Many people live with atherosclerosis for years without knowing it, and the condition may not surface until a major event, such as a heart attack, stroke, or the onset of peripheral artery disease symptoms like leg pain with walking.[2]
The Four Stages of Atherosclerosis
Medical researchers describe the progression of atherosclerosis in four distinct stages, each representing deeper damage within the artery wall.
Stage 1 – Endothelial Damage
The process begins with injury to the endothelium, the thin cellular layer lining the inside of arteries. This damage is often invisible on standard tests and may start as early as childhood or adolescence in people with risk factors. The injured area becomes a site where cholesterol and inflammatory cells begin to gather.
Stage 2 – Fatty Streak Formation
The first visible sign of atherosclerosis is a fatty streak: a yellowish deposit of lipid-filled foam cells along the inner artery wall. Fatty streaks have been detected in autopsies of teenagers, confirming that atherosclerosis can begin much earlier than most people realize.[3] These early deposits do not typically cause symptoms or restrict blood flow on their own, but they set the stage for more serious buildup.
Stage 3 – Fibrous Plaque Development
As foam cells accumulate and die, the debris builds into a more substantial plaque. Smooth muscle cells migrate to the site and form a fibrous cap over the growing lesion. This fibrous cap acts as a covering, but the plaque beneath continues to expand. At this stage, the artery may begin to narrow, and blood flow can become partially restricted, though many people still do not experience symptoms.
Stage 4 – Plaque Rupture or Severe Blockage
In the most advanced stage, the fibrous cap over a plaque can rupture or erode. When this happens, the body responds as though there is an injury, triggering rapid clot formation at the site. This clot can partially or completely block the artery, cutting off blood flow to the tissue it supplies.
In the arteries of the heart, this process causes a heart attack. In the arteries of the legs, severe blockage leads to the advanced stages of PAD, including critical limb ischemia, a condition where tissues are deprived of oxygen-rich blood.[4]
How Fast Does Atherosclerosis Progress?
Atherosclerosis usually develops slowly over many years, often beginning in adolescence and progressing quietly without symptoms. By middle age, many people already have some plaque buildup in their arteries, even if they feel healthy.
However, progression is not always gradual. Studies show that plaque can build more quickly during the 40s and 50s, when factors such as aging, metabolic changes, and long-term lifestyle habits begin to have a greater impact on vascular health.
Certain risk factors can significantly accelerate this process, including:
- Smoking, which damages artery walls and promotes plaque buildup
- Diabetes, especially when blood sugar is not well controlled
- High blood pressure, which places stress on artery walls
- High LDL (“bad”) cholesterol, which contributes to plaque formation
The more risk factors a person has, the faster atherosclerosis may progress and increase the likelihood of conditions such as peripheral artery disease (PAD), heart disease, and stroke.
How Atherosclerosis Leads to Peripheral Artery Disease
When atherosclerosis develops in the arteries supplying the legs and lower extremities, it becomes the primary driver of peripheral artery disease (PAD). As plaque narrows these arteries, the muscles in the legs receive less oxygen-rich blood, particularly during activity.
The classic symptom is claudication, a cramping or aching pain in the calves, thighs, or buttocks that begins with walking and subsides with rest. As the stages of PAD advance, symptoms may occur at rest, wounds on the feet or legs may heal poorly, and in the most severe cases, tissue damage can become irreversible.
Since atherosclerosis and PAD share the same underlying mechanism, the speed of atherosclerosis progression directly affects how quickly PAD may develop or worsen. This connection also means that someone with known atherosclerosis in their heart arteries likely has plaque building in their leg arteries as well, even without leg symptoms yet.
Can You Slow Atherosclerosis Progression?
While atherosclerosis cannot be reversed, its progression can be slowed and in some cases partially stabilized with the right approach. The goal of treatment is to reduce the rate of new plaque formation, lower the risk of plaque rupture, and maintain adequate blood flow.
Medical and Lifestyle Approaches
Cholesterol-lowering medications, particularly statins, are among the most studied interventions for slowing atherosclerosis. They reduce LDL cholesterol in the bloodstream, limit the inflammatory response in artery walls, and may help stabilize existing plaques by strengthening the fibrous cap.[7]
Blood pressure management reduces the mechanical stress on damaged artery walls. Blood sugar control in people with diabetes limits the ongoing damage to the endothelium. From a lifestyle standpoint, quitting smoking is consistently identified as the most impactful single change a person can make for their vascular health. Regular physical activity supports circulation and helps manage cholesterol, blood pressure, and weight. A diet lower in saturated fats and higher in fiber-rich foods can help reduce LDL levels. These approaches will not eliminate existing plaque, but they can meaningfully alter the trajectory of the disease.
When to See a Vascular Specialist
Since atherosclerosis progresses silently for so long, many people do not seek evaluation until symptoms are already significant. But earlier detection creates more options for intervention. A vascular specialist can assess your artery health using non-invasive testing, including the ankle-brachial index (ABI), a simple comparison of blood pressure in the ankle and arm that can reveal arterial narrowing in the legs. This test aims to evaluate whether the blockage is due to PAD to help the vascular specialists suggest minimally invasive treatment options. If you have known PAD risk factors, including smoking history, diabetes, high blood pressure, high cholesterol, or a family history of vascular disease, a vascular evaluation may be appropriate even without symptoms. If you experience leg pain, cramping, or fatigue that starts with activity and improves with rest, these may be early signals worth discussing with a vascular specialist. Understanding where you stand on the progression of atherosclerosis can help you and your care team make more informed decisions.
FAQs About Atherosclerosis Progression
Can atherosclerosis happen suddenly?
Atherosclerosis itself is a gradual process that builds over decades. However, the most serious complications, like plaque rupture that causes a heart attack or sudden worsening of PAD symptoms, can happen quickly once the disease is advanced. The underlying buildup develops slowly, but critical events can occur without much warning.
What are the four stages of atherosclerosis?
The four stages are endothelial damage, fatty streak formation, fibrous plaque development, and plaque rupture or severe blockage. Each stage represents deeper structural change within the artery wall, progressing from minor injury to significant narrowing or complete blockage.
Is a 70% artery blockage serious?
Yes. A 70% narrowing of an artery is considered hemodynamically significant, meaning it is likely to restrict blood flow enough to cause symptoms. In the leg arteries, this level of blockage may cause pain during walking or other signs of peripheral artery disease. A vascular specialist can evaluate severity and discuss treatment options.
How do you slow the progression of atherosclerosis?
Slowing progression typically involves managing key risk factors. Quitting smoking, lowering LDL cholesterol through diet or medication, controlling blood pressure and blood sugar, and increasing physical activity are all approaches that may help slow plaque buildup and reduce the risk of serious events.
At what age does atherosclerosis typically start?
Research confirms that fatty streaks, the earliest form of atherosclerotic change, can appear in the teenage years. More advanced plaque develops through the 20s and 30s. By age 40, approximately half of adults have some degree of cholesterol deposits in their arteries, though most will not yet have symptoms.
Can you have atherosclerosis without any symptoms?
Yes. The early stages of atherosclerosis rarely cause symptoms, and many people live with moderate plaque buildup for years without any signs of the disease. This is why screening and risk assessment are particularly important for people with known risk factors like smoking, diabetes, or high blood pressure.
How does atherosclerosis differ from arteriosclerosis?
Arteriosclerosis is a broad term for any stiffening or hardening of the arteries that can occur with aging. Atherosclerosis is a specific type caused by plaque buildup inside the artery walls. Atherosclerosis is the most clinically significant form and the primary cause of conditions like coronary artery disease, stroke, and peripheral artery disease.
References
- National Institutes of Health, StatPearls. “Atherosclerosis.” NCBI Bookshelf, 2023. https://www.ncbi.nlm.nih.gov/books/NBK507799/
- Cleveland Clinic. “Atherosclerosis.” Cleveland Clinic Health Library, 2025. https://my.clevelandclinic.org/health/diseases/16753-atherosclerosis-arterial-disease
- American Journal of Medicine. “The Pathology of Atherosclerosis: Plaque Development and Plaque Responses to Medical Treatment.” 2009. https://www.amjmed.com/article/S0002-9343(08)01017-6/fulltext
- USA Vascular Centers. “Stages of Peripheral Artery Disease (PAD).” https://www.usavascularcenters.com/pad-vascular-health/stages-of-pad/
- WebMD. “Atherosclerosis: Your Arteries Age by Age.” 2024. https://www.webmd.com/heart-disease/features/atherosclerosis-your-arteries-age-by-age
- Medical News Today. “Atherosclerosis rapidly develops between ages 40 to 50.” April 2020. https://www.medicalnewstoday.com/articles/atherosclerosis-rapidly-develops-between-ages-40-to-50-research-shows
- National Institutes of Health, StatPearls. “Atherosclerosis.” NCBI Bookshelf, 2023. https://www.ncbi.nlm.nih.gov/books/NBK507799/
