Aortic valve stenosis is a condition where the valve between the heart and the body’s main artery becomes narrow and stiff, forcing the heart to work much harder to pump blood throughout the body. This common heart valve problem particularly affects older adults and can progress from a quiet, symptomless phase to a life-threatening condition if left untreated.

How Common Is Aortic Stenosis?

Aortic stenosis is a widespread condition, especially among older populations. The prevalence of calcific aortic sclerosis, which is the thickening and hardening of the valve without significant blockage, affects about one to two percent of people aged 65 or younger. However, this number jumps dramatically with age. In individuals over 65, the prevalence ranges from nine to 45 percent depending on the study, and about six percent or more of people aged 75 or older have significant aortic stenosis.^[1][4]

Between two and nine percent of people older than 75 years have severe aortic stenosis. The condition is more common in men than in women. Many people don’t even know they have it until symptoms appear or it’s discovered during routine medical screening. In rare instances, children can be born with conditions that cause aortic valve stenosis to develop earlier in life.^[3][4]

What Causes Aortic Valve Stenosis?

The aortic valve sits between the lower left chamber of your heart and the aorta, which is the body’s largest artery. Normally, this valve has three flaps, called leaflets, that open to let blood pass through and then seal shut to prevent blood from flowing backward. When these leaflets become narrowed, thickened, or blocked, the condition is called aortic stenosis.^[1]

In adults, aortic stenosis has three main causes. The most common cause in people over 65 is simple wear and tear due to aging. Over many years, calcium deposits can build up on the valve, making it stiff and narrow. This process is similar to how arteries can harden with age.^[3]

Another cause is damage from infections. When bacteria from untreated infections, particularly strep throat or scarlet fever, reach the bloodstream, they can settle on heart valves. This can lead to rheumatic fever, a condition that damages the heart valves. In developing countries, rheumatic valve disease is actually the most common cause of aortic stenosis. The damage may take years or even decades to become apparent.^[3][4]

In younger adults, particularly those under 70, the most common cause is being born with an abnormal valve structure. Some people are born with a bicuspid aortic valve, meaning their valve has only two leaflets instead of three. This abnormal structure causes the valve to wear out faster and develop stenosis earlier in life.^[4]

Who Is at Higher Risk?

Several factors increase the likelihood of developing aortic valve stenosis. Being male puts you at higher risk, as does advancing age, particularly being older than 65. The condition becomes exponentially more common as we age, with the aortic valve typically opening and closing several billion times over a person’s lifespan.^[1][3]

Having certain inherited or chronic conditions also raises risk. Rare conditions like Paget’s disease of the bone, kidney failure, and familial hypercholesterolemia (a genetic condition causing very high cholesterol) can contribute to valve problems. Aortic stenosis is also linked to autoimmune or inflammatory diseases such as lupus and rheumatoid arthritis. Mineral metabolism disturbances, particularly end-stage renal disease, have been shown to contribute to valve calcification.^[3][4]

People born with congenital heart defects, especially a bicuspid aortic valve, face higher risk of developing stenosis. Additionally, having had untreated streptococcal infections in childhood increases the chance of developing rheumatic fever, which can damage heart valves over time.^[4]

Recognizing the Symptoms

Aortic stenosis typically develops slowly over many years. During this long period, which can last 10 to 20 years, people often have no symptoms at all. Survival during this asymptomatic phase is comparable to that of people without the condition. However, once symptoms begin, the situation changes dramatically.^[4]

The symptoms of aortic stenosis tend to progress from less severe to more severe. Early on, people may experience fatigue that disrupts their normal activities. They might notice their heart beating in an unpleasant way, a sensation called heart palpitations. Some people develop swelling in their feet, ankles, or lower legs.^[3]

As the condition worsens, more serious symptoms emerge. Angina, or chest pain, is common. This can feel like squeezing, pressure, or discomfort, and it may extend beyond the chest to the neck, jaw, arm, or abdomen. Many people experience shortness of breath, particularly during physical activity. Some may feel dizzy, lightheaded, or even faint, sometimes without any warning signs.^[3][6]

It’s important to note that older adults, who typically have decreased activity levels, may experience a delayed onset of symptoms. They might relate their symptoms to other coexisting conditions or simply to getting older, which can delay diagnosis and treatment.^[13]

Can Aortic Stenosis Be Prevented?

While you cannot completely prevent aortic stenosis, especially when it’s related to aging or congenital factors, certain lifestyle choices and health measures may help slow its progression or reduce your risk of developing it.^[8]

Taking good care of your teeth and gums is surprisingly important. Getting regular dental checkups and maintaining good dental hygiene matters because bacteria from infected teeth and gums can spread through the bloodstream to heart valves, potentially causing damage.^[22]

Eating heart-healthy foods can make a difference. This includes plenty of vegetables, fruits, nuts, beans, lean meat, fish, and whole grains. Limiting sodium, alcohol, and sugar is also beneficial. Staying physically active, at a level your doctor recommends as safe, helps maintain overall heart health.^[22]

Not smoking is crucial for heart health. If you smoke, quitting is one of the best things you can do for your heart and valves. Maintaining a healthy weight and managing other health problems, particularly high blood pressure, high cholesterol, and diabetes, also plays an important role in heart valve health.^[22]

Getting vaccinated against COVID-19, influenza, and pneumonia helps protect against infections that could potentially affect the heart. Promptly treating infections, particularly strep throat, with appropriate antibiotics can prevent rheumatic fever, which is a major cause of heart valve damage in some parts of the world.^[22]

How the Condition Affects Your Body

Understanding what happens inside your body when you have aortic stenosis helps explain why the condition is serious. The aortic valve normally opens three to five square centimeters during each heartbeat. When stenosis develops, this opening becomes narrower, creating an obstruction to blood flow leaving the heart.^[1]

Your heart responds to this narrowing by working harder to push blood through the restricted opening. Over time, the heart muscle, particularly the left ventricle (the heart’s main pumping chamber), becomes thicker and stronger in an attempt to compensate. This thickening is called left ventricular hypertrophy. While this adaptation helps maintain adequate blood pressure and oxygen delivery to your body initially, it creates new problems.^[12]

The thickened heart muscle becomes stiffer and less flexible. This affects how well the heart can relax and fill with blood between beats, a problem called diastolic dysfunction. The upper chamber of the heart, the left atrium, must then contract more forcefully to fill the stiff ventricle with enough blood. This is why maintaining a normal heart rhythm becomes especially important in people with aortic stenosis.^[12]

As stenosis progresses and becomes more severe, these compensatory mechanisms eventually fail. The heart can no longer pump effectively against the obstruction, leading to reduced blood flow throughout the body. This means less oxygen reaches your organs and tissues, causing symptoms like fatigue, shortness of breath, and chest pain. The heart itself may not receive enough oxygen-rich blood, leading to angina. If blood backs up behind the failing heart, it can cause fluid accumulation in the lungs and legs.^[12]

The rate at which aortic stenosis progresses varies considerably between individuals. For some people, the condition develops slowly over several years. For others, it can worsen much more rapidly. In severe cases, there’s a risk of sudden death. Once damage to the heart muscle occurs, it may not be fully reversible even after treatment, which is why doctors often advise not delaying treatment.^[3]