Atherosclerosis: Symptoms, Causes & Treatment

Written by: Editorial Team

Medically reviewed by: Dr. Seshi Vardhan Janjirala - Consultant Interventional Cardiologist

Overview | Epidemiology | Types | Symptoms | Causes | Risk Factors | Complications | Diagnosis | Treatment | Prevention | Atherosclerosis vs Arteriosclerosis | FAQs | When to consult a Doctor

Atherosclerosis definition

Atherosclerosis is a chronic disease of the arteries in which fatty deposits (plaques) made of cholesterol, calcium, and inflammatory cells gradually build up on the inner walls of blood vessels. This fat buildup causes the arteries to become narrow and harden, hence reducing blood flow to vital organs and tissues. Symptoms depend on the arteries affected. Insufficient blood flow to the heart causes chest pain or shortness of breath; if brain arteries are involved, it may lead to transient ischemic attacks (TIA) or stroke symptoms; and reduced blood flow to the limbs can cause claudication (leg pain during walking).

The causes and risk factors are high cholesterol levels, high blood pressure, diabetes, obesity, smoking, physical inactivity, an unhealthy diet, and a family history of cardiovascular disease. Complications can include acute coronary syndromes, peripheral artery disease, ischemic stroke, aortic aneurysm, chronic kidney disease, and increased cardiovascular mortality.

A cardiologist or vascular specialist, a doctor specialised in heart and blood vessel diseases, can accurately diagnose atherosclerosis and guide appropriate treatment and preventive strategies.

Atherosclerosis is a major global health problem and the leading underlying cause of cardiovascular diseases such as heart attack and stroke. According to the World Health Organisation (WHO), cardiovascular diseases account for nearly 32% of all deaths globally, with atherosclerosis responsible for most of these cases. The highest burden of atherosclerosis-related deaths occurs in low- and middle-income countries, that accounts around 75% of global cardiovascular mortality. Although high-income countries have achieved declining death rates through prevention and advanced care, the prevalence continues to rise worldwide due to population ageing and lifestyle changes.

Atherosclerosis is the leading cause of death in India, currently accounting for nearly 30–35% of all fatalities. It is uniquely characterised by a premature onset, with heart attacks occurring 5–10 years earlier than in Western populations; notably, 25% of cases strike individuals under the age of 40. The epidemic is driven by a high prevalence of diabetes, hypertension (affecting 1 in 4 adults), and a distinct lipid profile of high triglycerides and low HDL. Prevalence is significantly higher in urban areas (~10–12%) compared to rural regions (~4–6%).

Atherosclerosis is a systemic, progressive disease, but it is described as different types based on the arterial location involved, because involvement of different arteries produces distinct clinical features, complications, and syndromes. This location-based classification helps in understanding disease presentation, diagnosis, and management. The different types of atherosclerosis are discussed below:

• Coronary atherosclerosis
• Carotid artery atherosclerosis
• Atherosclerosis peripheral arterial disease (PAD)
• Atherosclerosis of the renal artery
• Aortic atherosclerosis
• Vertebral artery atherosclerosis
• Intracranial atherosclerosis 

Coronary atherosclerosis: The buildup of atherosclerotic plaques in the coronary arteries that supply blood to the heart muscle. As plaques narrow the arterial lumen, due to this oxygen delivery to the myocardium decreases, especially during increased demand such as exercise or stress. Because the heart is highly sensitive to reduced blood flow, coronary involvement is one of the most common site of atherosclerosis.

Carotid artery atherosclerosis: Carotid atherosclerosis involves plaque formation in the carotid arteries, which supply blood to the brain. Progressive narrowing can reduce cerebral perfusion, while unstable plaques may rupture and release emboli that travel to cerebral vessels. This type commonly presents with transient ischemic attacks or ischemic stroke. 

Atherosclerosis peripheral arterial disease (PAD): This affects the arteries supplying the lower limbs, and less commonly the upper limbs. This reduces blood flow to skeletal muscles leads to ischemic pain during activity, known as intermittent claudication. In advanced disease, blood flow may be insufficient even at rest, resulting in non-healing ulcers, tissue necrosis, or gangrene. 

Atherosclerosis of the renal artery: Renal atherosclerosis occurs when plaques narrow one or both renal arteries, which reduces blood flow to the kidneys. The kidneys release hormones, leading to secondary hypertension that is often resistant to treatment. Chronic reduction in renal perfusion may also cause progressive renal ischemia and loss of kidney function.

Aortic atherosclerosis: Aortic atherosclerosis occurs when fatty deposits build up in the aorta. This buildup happens most often in the lower (abdominal) part of the aorta. At first, it may not cause any symptoms. However, over time, the plaques can weaken the wall of the blood vessel, increase the risk of a bulge or widen, called an aneurysm.

Vertebral artery atherosclerosis: This occurs when fatty buildup develops in the vertebral arteries, which carry blood to the back part of the brain. This area controls important functions such as balance, coordination, and vision. When these arteries get narrowed, less blood reaches the brain, which can cause symptoms like dizziness, spinning sensations, blurred or double vision, trouble with balance or walking, and even fainting.

Intracranial atherosclerosis: Intracranial atherosclerosis refers to the development of atherosclerotic plaques in the arteries located within the cranial cavity and vertebral arteries. Plaque formation in these vessels leads to progressive narrowing of the arterial lumen, reducing blood flow to brain tissue. Clinically, it is a major cause of ischemic stroke and transient ischemic attacks.

Atherosclerosis often develops slowly and may cause no symptoms initially. Symptoms usually appear when the arteries become severely narrowed or completely blocked. The signs and symptoms of atherosclerosis depend on which arteries are affected:

Atherosclerosis cardiovascular disease symptoms are:

• Chest pain or pressure (Angina) 
• Shortness of breath 
• Fatigue 
• Heart attack (Myocardial infarction) 

Atherosclerosis brain symptoms (carotid arteries) are:

• Sudden weakness or numbness 
• Trouble speaking or understanding speech 
• Dizziness or sudden vision problems 
• Stroke or mini-stroke (TIA) 

Atherosclerosis symptoms in the legs

• Claudication (pain or cramping in legs) 
• Coldness or numbness in legs 
• Slow-healing wounds on feet or toes 

Atherosclerosis – Kidney Arteries

• High blood pressure 
• Reduced kidney function 

Atherosclerosis cardiovascular disease symptoms are:

• Chest pain or pressure (angina): Atherosclerosis narrows the coronary arteries, reducing blood flow to the heart muscle. During exertion or stress, the oxygen supply becomes insufficient, leading to myocardial ischemia and the characteristic pressure-like chest pain called angina.

• Shortness of breath (SOB): This happens because decreased coronary blood flow decreases myocardial contractility, which reduces the heart's capacity to pump effectively. As cardiac output decreases, blood backs up into the pulmonary circulation, causing pulmonary congestion and dyspnea (sensation of breathlessness).

• Fatigue: This is a result of decreased cardiac output caused by chronic myocardial ischemia. When the heart cannot pump sufficient oxygenated blood to meet the body’s metabolic needs, skeletal muscles and other tissues receive less oxygen, leading to early fatigue and reduced exercise tolerance.

• Heart attack (Myocardial infarction): When an atherosclerotic plaque ruptures, a blood clot forms and abruptly blocks a coronary artery. This sudden loss of blood supply causes myocardial infarction, commonly known as a heart attack.

Atherosclerosis brain symptoms (carotid arteries) are:

• Sudden weakness or numbness: Atherosclerotic narrowing or plaque rupture in cerebral or carotid arteries reduces blood flow to specific areas of the brain that control motor and sensory functions. Ischemia of these regions results in sudden weakness or numbness on the opposite side of the body.

• Trouble speaking or understanding speech: When atherosclerosis compromises blood flow to language centres of the brain, such as Broca’s or Wernicke’s areas, speech production or comprehension becomes impaired, leading to difficulty understanding words.

• Dizziness or sudden vision problems: Reduced blood flow to areas that are responsible for balance, coordination, or vision causes dizziness, loss of balance, blurred vision, or sudden visual field defects.

• Stroke or mini-stroke (TIA): Severe or prolonged interruption of cerebral blood flow can result in an ischemic stroke with permanent neurological damage.

Atherosclerosis symptoms in the legs

• Claudication (pain or cramping in the legs): Narrowing of leg arteries can limit blood flow to muscles during walking or exercise. The resulting muscle ischemia causes pain or cramping, which improves with rest.

• Coldness or numbness in the legs: Reduced arterial blood supply decreases skin and nerve perfusion, making the affected limb feel cold and numb compared to the normal side.

• Slow-healing wounds on feet or toes: Poor blood flow reduces oxygen and nutrient delivery needed for tissue repair. Since the blood flow is blocked, even minor cuts or ulcers heal slowly and are prone to infection.

Atherosclerosis – Kidney Arteries

• High blood pressure: When the arteries supplying the kidneys become narrowed, less blood reaches the kidneys. In response, the kidneys release hormones that raise blood pressure and cause the body to retain salt and water. This leads to high blood pressure that is difficult to control with medications.

• Reduced kidney function: Chronic reduction in blood flow to the kidneys causes renal ischemia and progressive damage to kidney tissue. This results in decreased glomerular filtration rate and worsening renal function.
  

Atherosclerosis is a chronic condition in which the arteries gradually become narrowed and hardened due to the buildup of plaques. This can reduce blood flow to vital organs and tissues, potentially leading to serious cardiovascular problems. It is a progressive disease that often develops silently over many years before symptoms appear. The causes of atherosclerosis are:

• Endothelial injury or dysfunction
• Lipid accumulation
• Chronic inflammation
• Smooth muscle cell migration and proliferation
• Plaque calcification

Endothelial injury or dysfunction

Endothelial injury or dysfunction is the main cause of atherosclerosis by damaging the inner lining of the arteries, making it easier for harmful substances to enter. When this lining gets injured, due to factors like high blood pressure, smoking, or diabetes, it loses its protective barrier function and becomes sticky, which attracts immune cells and allows cholesterol to penetrate into the artery wall. Hence, initiating the disease process.

Lipid accumulation

Atherosclerosis is caused by the deposition of lipid, which happens when excess fats, especially LDL or bad cholesterol, get trapped in the damaged artery wall. These lipids oxidise and form fatty streaks, which attract more immune cells that absorb them up, turning into foam cells that enlarge the deposit. Over time, this growing lipid contributes to plaque formation, stiffening and blocking arteries.

Chronic inflammation

Atherosclerosis is caused by chronic inflammation. Foam cells, endothelial cells, and other immune cells release inflammatory mediators such as cytokines and growth factors. These substances attract more inflammatory cells and maintain a continuous inflammatory response, leading to further damage of the arterial wall and progression of the plaque.

Smooth muscle cell migration and proliferation

Inflammatory signals stimulate smooth muscle cells from the arterial media to migrate into the intima. These cells proliferate and produce collagen and extracellular matrix components. This results in the formation of a fibrous cap over the lipid core, contributing to plaque enlargement and narrowing of the arterial lumen.

Plaque calcification

Calcium deposits form within atherosclerotic plaques after prolonged inflammation and plaque maturation. This calcification makes the artery wall harder and less elastic, exacerbating luminal narrowing. This raises the risk of decreased blood flow, plaque rupture, thrombosis, and significant clinical events.

The development of atherosclerosis is not sudden; it progresses gradually as a result of various risk factors that damage the arterial walls, alter lipid metabolism, and promote chronic inflammation. These risk factors can be categorised as non-modifiable and modifiable. Together, they increase the likelihood of plaque formation and the risk of cardiovascular disease. The following are the major risk factors of atherosclerosis:

Atherosclerosis non modifiable risk factors 

• Older age
• Gender
• Family history of atherosclerosis or heart disease
• Ethnicity
• Certain medical conditions

Older age: The risk increases with advancing age because arteries gradually lose elasticity and are exposed to the long-term effects of lipid accumulation and inflammation. Over time, this repeated endothelial injury allows plaques to develop and progress, making older individuals more susceptible to arterial narrowing and cardiovascular events.

Gender: Males are generally at a higher risk of developing atherosclerosis at an earlier age compared to females. Female hormones in premenopausal women have a protective effect by improving lipid profiles and maintaining endothelial function. After menopause, this protection declines, and the risk in women increases significantly.

Family history of atherosclerosis or heart disease: A family history indicates a genetic predisposition to conditions such as hyperlipidemia, hypertension, or diabetes. These inherited traits increase the likelihood of endothelial dysfunction and lipid accumulation, raising the risk of early-onset atherosclerosis.

Ethnicity: Certain ethnic groups have a higher prevalence of atherosclerosis due to genetic factors, socioeconomic conditions, and lifestyle patterns. These factors may influence cholesterol levels, blood pressure regulation, and susceptibility to metabolic disorders.

Certain medical conditions: Conditions such as diabetes mellitus, high blood pressure, and genetic lipid disorders accelerate atherosclerosis.

Modifiable risk factors of atherosclerosis

• Physical inactivity
• Unhealthy diet
• Smoking and other tobacco use
• Excessive alcohol consumption
• Excess weight or obesity

Physical inactivity: Lack of regular physical activity causes obesity, insulin resistance, and affects cholesterol levels. It reduces high-density lipoprotein (HDL) cholesterol and increases low-density lipoprotein (LDL) cholesterol, which promotes lipid accumulation and endothelial dysfunction.

Unhealthy diet: Diets that are high in saturated fats, trans fats, salt, and refined sugars raise LDL cholesterol, blood pressure, and inflammation, which accelerate lipid deposition in arteries and promote plaque formation. 

Smoking and other tobacco use: Smoking directly damages the endothelium, increases LDL oxidation, and promotes inflammation, which reduces oxygen delivery and increases blood clot formation.

Excessive alcohol consumption: Chronic excessive alcohol intake raises blood pressure, triglyceride levels, and body weight, and these changes contribute to endothelial injury, inflammation, and lipid imbalance.

Excess weight or obesity: Obesity is associated with dyslipidemia, hypertension, and insulin resistance. Excess adipose tissue releases inflammatory mediators that promote chronic inflammation and endothelial dysfunction.