Key takeaways

  • Shortness of breath, especially during activities that increase the heart rate, can be an early indicator of HCM.
  • Chest pain, which often feels like tightness or pressure, may arise during physical activity because the thickened heart muscle does not receive enough oxygen.
  • Swelling in the legs, feet, or ankles can also signify HCM, as the heart’s reduced efficiency in pumping blood leads to fluid retention in the lower body.

Hypertrophic cardiomyopathy (HCM) is an inherited heart condition that involves thickening of the wall of the heart’s left ventricle. The left ventricle is the chamber of the heart responsible for pumping oxygenated blood to the rest of the body.

In the early stages of HCM, people may not experience symptoms. However, thickening of the heart tissue can eventually affect the heart’s function and may produce a range of symptoms. Often, these symptoms are first noticeable during or after physical activity.

Below, we discuss some warning signs of HCM and explain when to contact a healthcare professional.

According to the American College of Cardiology, many people with HCM first notice symptoms during exercise.

One such warning sign is unusual shortness of breath during activity. While it’s normal to breathe hard during vigorous exercise, experiencing shortness of breath during less strenuous activity can indicate a problem. In HCM, shortness of breath may be subtle at first and worsen over time. A person may also notice chest tightness and lightheadedness.

In HCM, shortness of breath may arise while a person is climbing stairs, hiking, riding a bike, or doing another activity that increases their heart rate.

Like shortness of breath, chest pain in HCM may first arise during activity. This pain may occur because the thickening of the heart muscle can affect the amount of oxygen the heart receives.

In people with HCM, this pain may feel like tightness or pressure in the chest.

Excessive fatigue is another warning sign of HCM. There are many reasons why HCM may lead to fatigue, including:

  • inefficient pumping of blood, which deprives tissues of oxygen and nutrients
  • buildup of fluid in the lungs
  • a blockage of blood flow out of the heart
  • irregular heart rhythms

According to the Hypertrophic Cardiomyopathy Association, this common symptom may be particularly noticeable during hot weather, after exercise, and when a person is dehydrated.

However, typical daily activities may also leave people with HCM feeling exhausted.

A person experiencing heart palpitations may feel as if their heart is pounding, fluttering, or skipping a beat.

In HCM, heart palpitations may occur because the heart is working harder to pump blood as a result of the thickening of the left ventricle or because the condition has created scarring (fibrosis) that affects the heart’s electrical system.

Occasional heart palpitations are common and not always a cause for concern. However, a person may want to consult a healthcare professional if they are experiencing any of the following:

  • new or persistent palpitations
  • palpitations during or after exercise
  • palpitations alongside other symptoms

A person with HCM may experience episodes of lightheadedness and fainting if the condition interrupts blood flow to the brain. Disruptions in blood flow may occur as a result of a blockage or an irregular heart rhythm.

Someone who is experiencing lightheadedness may feel faint and possibly nauseated. They may also experience temporary blurring of their vision.

If a person feels lightheaded, they should try to lie down to avoid fainting or falling. When the symptoms subside, it is best to stand up slowly. Drinking fluids and consuming sugar may also help relieve these symptoms.

The heart’s less efficient pumping in HCM can lead to a buildup of blood and fluid, which can cause swelling throughout the body.

If a person experiences swelling in the lower body, including in the legs, feet, and ankles, it could be a warning sign of HCM. Swelling may also occur in the abdomen.

Like the other signs of HCM, swelling may be particularly noticeable after physical activity.

HCM is a genetic condition that can worsen over time. Depending on the condition’s severity, a person may not receive an HCM diagnosis until adulthood.

Young adults and older children with HCM can experience many of the same warning signs as other adults, including:

  • shortness of breath
  • fatigue
  • dizziness
  • fainting
  • chest pain
  • heart palpitations

Babies with HCM may experience:

  • excessive sweating
  • breathing difficulties
  • low muscle tone
  • reduced growth
  • trouble feeding

It can be tempting to dismiss some of the symptoms above, assuming that they are due to aging, a lack of fitness, or another common cause. But in some cases, it may be advisable for a person to consult a healthcare professional.

Someone may want to seek medical advice in any of the following situations:

  • They have a family history of HCM and notice any of these warning signs.
  • They experience new or worsening episodes of any of these symptoms.
  • Their symptoms interfere with their daily life.

If symptoms are severe or appear suddenly, a person should seek immediate medical attention, especially for chest pain or difficulty breathing.

HCM is a genetic heart disease that involves thickening of the heart tissue. The structural changes in the heart can cause it to pump blood less efficiently and may lead to a wide range of symptoms.

People with HCM may not experience any symptoms. In those who do, possible warning signs of HCM can include:

  • shortness breath
  • chest pain
  • fatigue
  • heart palpitations
  • swelling

If a person has new or worsening symptoms of HCM, they may want to speak with a healthcare professional — especially if they have a family history of the condition.