The cardiovascular system involves how the heart processes nutrients and oxygen in the blood, a process known as coronary circulation. The body’s circulation system consists of the coronary veins and coronary arteries. With age or an underlying medical condition, the body’s circulation system does not work as effectively, leading to potential health complications. This comprehensive guide to cardiology is designed to cover the basics of cardiology and what a cardiologist does.
What Is a Cardiologist and What Do They Do?
A cardiologist is a doctor who specializes in treating diseases and complications of the cardiovascular system. These physicians often work with the blood vessels and heart. Some of the most common cardiac conditions a cardiologist may treat include congenital heart defects, coronary artery disease and heart and vascular disease. A cardiologist may also treat patients experiencing heart attacks, heart failure and other heart complications.

These professionals may work with patients at a private practice, in a hospital or even in a university setting. A cardiac surgeon, also known as a cardiothoracic surgeon, is a cardiologist who has received additional training to perform various treatments, procedures and surgeries on the heart. In some cases, a cardiologist may refer a patient to a cardiac surgeon for more severe complications or complex surgical procedures.
The Centers for Disease Control and Prevention (CDC) estimates approximately 805,000 people in the United States have a heart attack each year, with 605,000 of these being a first heart attack. The other 200,000 are people experiencing secondary heart attacks. In addition to heart attacks, heart disease is one of the leading causes of death in the United States, making cardiologists incredibly important for maintaining proper health.
While a cardiologist’s responsibilities will vary from physician to physician, some of the most common duties include:
- Patient visits: One of the most obvious aspects of a cardiologist’s job is seeing patients to evaluate their heart health. These doctors regularly see patients and monitor various signs to assess if a patient’s heart is functioning normally. A primary or internal medicine doctor may recommend a patient to see a cardiologist if they expect a patient may be experiencing symptoms of a cardiac condition. Some cardiologists may also be called to emergency rooms if patients suffer a heart attack, heart failure or severe arrhythmia.
- Patient care: After determining what is wrong with a patient, a cardiologist must decide on appropriate treatment. A cardiologist may perform various non-surgical cardiac treatments to improve a patient’s health and minimize the severity of symptoms. In more severe cases, a cardiologist may recommend a patient see a cardiac surgeon or another specialist if their condition affects other parts of the body. Medication, non-surgical treatments and lifestyle changes are common treatment modalities a cardiologist may recommend to patients.
- Ordering and interpreting tests: A cardiologist may also need to order various tests to assess a patient’s health accurately. These physicians will also need to effectively view and interpret these test results to detect or diagnose potential heart complications. A common cardiological exam is an echocardiogram, which is a test that can capture a picture of the heart’s structure to determine if it is functioning properly. There are numerous tests a cardiologist needs to be familiar with to order and interpret effectively.
- Diagnosing conditions: These professionals can test, detect and diagnose many heart conditions, including heart defects and diseases. A cardiologist may perform various screenings or tests to examine a patient’s heart and any present symptoms to diagnose a heart condition. Detecting heart conditions in their earliest stages can improve the potential for effective treatment. Some cardiologists are trained in using a catheter to examine the heart and diagnose specific conditions.
- Treatment modalities: In addition to diagnosing cardiac conditions, a cardiologist can also provide many treatment modalities, ranging from medications to lifestyle changes. These doctors will also carefully explain the potential treatment options to patients and find one that works best for the patient’s unique symptoms and needs. In some cases, this may include pacemakers or placing stents.
- Surgical referral: While all cardiac surgeons are trained cardiologists, not all cardiologists are trained or licensed to perform cardiac surgery. In some cases, a cardiologist may refer you to a cardiac surgeon if you need surgery. For example, you may need to see a cardiac surgeon if you require coronary artery bypass grafting, a heart transplant or other heart-related surgeries.
- Follow-up appointments: In some cases, a cardiologist may need to see a patient if they have had major surgery or undergone a treatment that may require them to monitor their progress. Other patients may need to see a cardiologist every three to six months to determine whether a medication is working or monitoring a patient’s overall health. Sometimes, a patient with certain cardiac conditions may need to see a cardiologist before receiving another form of treatment or surgery, even if it does not directly affect the heart.
Cardiologist Education & Training

The field of cardiology can present a challenging and rewarding career, allowing physicians to work directly with patients to detect, diagnose and treat various heart conditions and diseases. Another important aspect of cardiology is prevention. The routine monitoring of patients and helping patients lead a healthy lifestyle through diet, exercise and heart education can lower the risk of various cardiovascular problems.
So, how do you become a cardiologist? To become a cardiologist, you will need to complete multiple levels of education and training:
Undergraduate Degree
The first step toward becoming a cardiologist in Houston, Texas, is to earn an undergraduate degree to apply for medical school. A standard undergraduate degree takes approximately four years to earn. While there is no specific undergraduate degree for becoming a cardiologist, many students choose to major in science-related fields, including chemistry, physics or biology.
Taking prerequisite premedical courses can build strong foundational knowledge of important topics related to the medical field. Because medical schools are quite competitive, earning an undergraduate degree in a respected field can improve the likelihood of getting accepted into the desired medical school. Additionally, maintaining a high grade-point average and building a strong resume is of the utmost importance.
Before applying to medical schools, candidates must study for and take the Medical College Admission Test (MCAT). The MCAT is a multiple-choice exam that has been an essential part of medical school admissions for over 90 years. The majority of medical schools in the U.S. require MCAT scores when candidates apply for entrance.
Medical School

After receiving an undergraduate degree, students will need to complete medical school to earn a Doctor of Osteopathy (DO) or Doctor of Medicine (MD) degree. In most cases, the first two years of medical school include courses in pathophysiology, biology, basic medicine, anatomy, physiology and more. The final two years of medical school include gaining real-life experience by working in medical settings and completing supervised internships.
During medical school, students will also take the first medical license exam, the United States Medical Licensing Exam (USMLE) Step 1. USMLE Step 1 is an intensive exam with over 300 questions that will play a large role in students’ future careers. The USMLE Step 1 score is used as a benchmark and metric for residency programs, which will use the information to determine if they invite students for an interview.
In the third year of medical school, students will transition into a hospital setting and use the knowledge they learned during their first two years in a real-world environment. Throughout the year, medical students will rotate through the core rotations, including general surgery, internal medicine, psychiatry, pediatrics and obstetrics and gynecology. This experience will help them choose which type of medicine they want to pursue.
Following the rotations, students will take their next licensing exam, the USMLE Step 2, in their final year of medical school. There are two aspects of the USMLE Step 2, which are clinical skills and knowledge. Each aspect is a different exam that students will take on separate days, taking about 18 hours to complete both sections.
Residency
Once students complete medical school, the next step toward becoming a cardiologist is a medical residency, a period of training where residents work in a hospital, clinic or medical setting and gain hands-on training and experience. Because cardiology is a sub-specialty of internal medicine, future cardiologists must complete an internal medicine residency.
Many candidates apply for a medical residency program in their final year of medical school. While there are many factors a medical residency program may consider, some of the most important include letters of recommendation, USMLE scores and personal statements. This is what every future doctor works toward over eight years in undergraduate and medical school.
The length of a residency will depend on the setting and the specialty, but some internal medicine residencies may take from four to eight years to complete. This time period also depends on if it is a surgical or non-surgical residency. For cardiology, internal medicine residency and cardiology training programs often cover radiographic imaging, vascular access, coronary anatomy, catheterization, congenital heart disease and more.
The overall length of school, training and residency will depend on the cardiac field a student is looking to enter. For example, cardiac surgeons may require five years of general surgery training before beginning a cardiothoracic program. On the other hand, a pediatric cardiologist will first need to study pediatric training before starting three to four years of specialized cardiology training.
Fellowship

Following an internship, a future cardiologist will then complete a fellowship in cardiology. This training is when a physician trains directly under a specialist to learn more about a medical subspecialty. During a fellowship, the learning physician is referred to as a fellow. For example, a cardiologist may complete a fellowship training program in advanced heart failure and heart transplantation to become an expert in that subspecialty.
A fellowship can provide detailed, hands-on training in a subspecialty for a unique advantage and to help physicians pursue a career in a specific niche within the cardiology field. In most cases, fellowship training lasts approximately three years and begins once a residency is completed.
Licensing
All physicians in the U.S. need to be licensed to practice. Though licensing requirements will vary state by state, physicians must graduate from an accredited medical school and pass a criminal background check. Additionally, physicians will need to pass USMLE exams. In some cases, continuing medical education may be required to renew a medical license. A cardiologist can become board-certified in the field of cardiology from the American Board of Internal Medicine.
Titles and Classifications

These credits are important aspects many patients look at when choosing a heart doctor in Houston, Texas. The American Board of Internal Medicine offers various certifications in cardiology, including interventional cardiology, cardiac electrophysiology and cardiovascular disease. To earn board certification in a subspecialty, candidates must first be certified in internal medicine by passing written examinations and meeting all prerequisites.
Because cardiology has numerous subspecialties, physicians can earn many titles and classifications depending on their unique career path. Some cardiologists may become trained in noninvasive cardiology, cardiothoracic surgery, invasive cardiology, pediatric cardiology and more. It all depends on their interests and goals.
Reasons to See a Cardiologist
There are many reasons to see a cardiologist regularly, including monitoring heart health to ensure there are no early signs or symptoms of various heart complications or diseases. Additionally, some patients may need to see a cardiologist if they notice painful, uncomfortable or long-term symptoms that may signify heart disease.
Some of the most common medical conditions a cardiologist may diagnose include:
1. High Cholesterol

While cholesterol is a vital part of the body’s cell-building process and system, excess cholesterol levels can be unhealthy and even dangerous. Having high cholesterol levels can cause a wax-like substance to build up in the blood vessels, restricting blood flow, which may increase a person’s risk of stroke or heart attack.
There are two main types of cholesterol, including high-density lipoproteins (HDL) and low-density lipoproteins (LDL). HDL is known as good or healthy cholesterol that brings excess cholesterol to the liver so the liver can flush the excess cholesterol from your system. On the other hand, LDL is often known as bad or unhealthy cholesterol because it can accumulate in your blood vessels and negatively impact blood flow.
Experiencing healthy cholesterol levels varies depending on numerous factors, including gender and age. On average, total cholesterol levels should be below 200 milligrams per deciliter (mg/dL). If you are diagnosed with high cholesterol, your cardiologist can help determine lifestyle changes and treatments that may be right for you.
2. Chest Pain
Some patients may experience chest pain, which can be a sign of a cardiac condition — chest pain resulting from a cardiac condition may feel dull, sharp or like a stabbing sensation. Additionally, patients may experience chest tightness and pressure and shortness of breath. A sensation of crushing or burning that radiates to the neck, back and arms may also occur.
If you experience intense, sudden or unexplained chest pain, you should seek emergency medical attention. In certain cases, chest pains may be a sign of heart disease, valve disease or aortic aneurysm. Other possible conditions include pericarditis, myocarditis, heart attack and cardiomyopathy.
3. Diabetes

The body needs glucose, as it is an important energy source. At the same time, our bodies naturally provide insulin, a hormone that helps move glucose from the blood to your body’s cells. Those with diabetes have a lack of adequate insulin levels, so the body cannot effectively remove excess glucose from the body.
There are two main forms of diabetes, including:
- Type 1 diabetes: In patients with type 1 diabetes, the body does not produce enough insulin. This type is an autoimmune disorder where the immune system prevents the pancreas from creating adequate insulin levels through an immune attack. Known as juvenile diabetes, type 1 diabetes typically develops or becomes apparent in children, adolescents and young adults — though it can develop at any age.
- Type 2 diabetes: In patients with type 2 diabetes, their bodies do not make any insulin or use insulin effectively. This form of diabetes may lead to various complications, including high blood sugar. While type 2 diabetes can occur at any age, it often develops in mid- to late life. Those who are overweight may be at a higher risk of developing type 2 diabetes.
4. Congestive Heart Failure
While the name may be misleading, congestive heart failure does not mean the heart is no longer working entirely. Instead, congestive heart failure means the heart is not pumping effectively or as efficiently as possible.
Because congestive heart failure is a long-term condition, it requires routine monitoring to evaluate your overall health. With age, your heart may become weaker or less efficient, causing increased pressure, slower blood movement and a great strain. When blood does not pump effectively, it will build up through the body, resulting in congestion.
The four stages of congestive heart failure are A, B, C and D. This is a progressive disease, meaning it worsens over time. Each stage of congestive heart failure can help patients and physicians understand related symptoms and potential treatment modalities. Some of the most common congestive heart failure symptoms include irregular or rapid heart rate, swelling in the ankles and shortness of breath.
Some patients may also experience coughing, wheezing, general weakness, dizziness or fatigue with congestive heart failure. The symptoms will vary from person to person and depend on the patient’s stage and type of disease. In certain cases, patients may not display or notice physical symptoms of congestive heart failure. On the other hand, some patients will notice mild, moderate or severe symptoms that may occur occasionally or remain constant.
5. Peripheral Artery Disease

PAD, or peripheral arterial disease, occurs when the arteries are narrowed as a result of fat buildup. When the blood flow through the arteries is reduced, it can cause various symptoms because your arms and legs cannot get the blood flow they need. While peripheral artery disease can affect any limb, it often occurs in the legs.
Those with peripheral artery disease may experience numbness, leg cramps, sores and even weakness when walking. As peripheral artery disease worsens, it may increase the risk of further complications, such as heart disease or limb ischemia. PAD is often caused by atherosclerosis, which causes cholesterol, fat and other substances to build up in the arteries.
The buildup from atherosclerosis negatively impacts the heart’s blood flow to the limbs. Other potential causes of peripheral artery disease include limb injuries or arterial inflammation. Other risk factors include high blood pressure, high cholesterol, obesity and diabetes. PAD is also common in both men and women with increased age, and patients with a family history of peripheral artery disease or who smoke may also be at an increased risk.
PAD affects approximately 8.5 million people in the U.S.
6. Coronary Artery Disease
This is a common heart disease in the U.S. CAD, or coronary artery disease, occurs when plaque accumulates and builds up in the heart’s arteries. Without proper blood flow through the arteries, a patient may be at a higher risk of stroke or a heart attack.
An early diagnosis and health care plan are essential for patients with coronary artery disease. That said, while a diagnosis is important, many cardiologists focus on prevention by improving heart health and lifestyle habits. The coronary arteries are major blood vessels responsible for transporting oxygen, blood and other nutrients to and from your heart. Any buildup in the coronary arteries can restrict healthy blood flow and result in chest pain and other serious heart conditions.
CAD symptoms may affect men and women differently and vary between patients. Some of the most common coronary artery disease symptoms include chest pain and shortness of breath. It may feel similar to indigestion or heartburn for some patients, leading them not to seek professional medical attention. Additional CAD symptoms include heart palpitations, nausea, sweating, weakness, dizziness, fast heartbeat and chest pressure.
7. High Blood Pressure

The body’s blood pressure measures the pressure exerted between each heartbeat and the amount of pressure within the arteries when your heart beats. Having healthy blood pressure means your blood is moving efficiently and your heart is pumping effectively. There are two categories of high blood pressure, including primary hypertension, which occurs over time.
About 47% of adults in the U.S. have high blood pressure. While there is no singular identifiable cause, risk factors for primary hypertension include genetics, physical changes and your environment. On the other hand, secondary hypertension emerges quickly and often results from an underlying medical condition. Specific medications, kidney disease and congenital disorders may increase a person’s risk for high blood pressure.
8. Arrhythmia
Arrhythmia is a term used to describe an unusual or irregular heart rhythm, such as beating too slow, beating too fast or even at an irregular rate. While it may be harmless, in some cases, it can be a serious medical condition that can even be life-threatening.
Within the body, the sinus node emits electrical impulses that initiate every heartbeat. Under normal circumstances, the impulses help the heart to effectively pump blood at a healthy rate. A heart rhythm problem occurs when the impulses do not occur correctly.
Arrhythmias are categorized based on where they occur, such as the ventricles or atria. Another important diagnostic element is the heart rate speed. For example, tachycardia is a fast heartbeat. On the other hand, a slow heartbeat is referred to as bradycardia.
9. Heart Attack

Every year, hundreds of thousands of Americans experience a heart attack. Research has found 20% of heart attacks are silent, meaning the person may not even be aware they are experiencing one. Also known as myocardial infarctions, heart attacks are one of the more serious cardiac conditions that require immediate medical attention.
During a heart attack, blood is prevented from flowing to the heart. Without blood flow, the heart muscle becomes damaged and can begin to die. To prevent severe heart damage, seeking emergency medical treatment is vital when someone expects they may be experiencing a heart attack. Unfortunately, the longer your heart goes without proper blood flow, the more severe the damage becomes.
10. Aneurysms
An aneurysm occurs when the wall of a blood vessel weakens, becoming distended or enlarged. If an aneurysm is left untreated, the blood vessels can eventually rupture, causing potentially life-threatening complications and damage. There are three main aneurysm types, including aortic aneurysms, peripheral aneurysms and cerebral aneurysms:
- Aortic aneurysms are among the most common aneurysm and can cause severe internal bleeding.
- Cerebral aneurysms occur from ballooning blood vessels in the brain, which can damage brain cells.
- Peripheral aneurysms involve other blood vessels through the body and may develop in the neck, behind the knee, in the groin or even near internal organs.
11. Stroke

A stroke is when the brain’s blood supply is reduced, diverted or interrupted completely. The three main types of strokes include transient ischemic attacks, ischemic strokes and hemorrhagic strokes. Around 87% of strokes are ischemic strokes, meaning the blood flow to the brain is blocked.
First, transient ischemic attacks are known as mini-strokes and occur from a temporary blockage that only lasts a few minutes. On the other hand, hemorrhagic stroke occurs when a blood vessel is ruptured or leaks. Finally, ischemic strokes are when a blood clot blocks blood flow or narrows an artery supplying blood to the brain.
12. Varicose Veins
These are enlarged blood vessels that appear just under the skin and may seem to bulge or twist. Any superficial vein may develop into a varicose vein, but the leg veins are some of the most common veins to become varicose. When the valves of a vein become damaged or weakened, swelling may occur as blood begins to pool.
While largely a cosmetic issue, varicose veins do pose the potential for serious health complications, including ulcers, bleeding and blood clots. A varicose vein may appear bluish or purplish and, in some cases, may be accompanied by leg heaviness, swelling, cramps, itchiness and other uncomfortable symptoms.
13. Arterial Blockage

As you age, your arteries may experience a buildup of plaque, fat and other materials that decrease the efficiency of the artery. As plaque builds up, the arteries begin to narrow, and blood flow is negatively impacted. When the plaque ruptures, patients may experience a stroke, heart attack or other life-threatening complications — the greater the blockage, the worse the damage. If the built-up plaque ruptures, you can experience a life-threatening heart attack or stroke.
A plaque buildup within your blood vessels is known as atherosclerosis, which can begin at a young age and worsen over time. In many patients, arterial blockage may not become apparent or cause complications until they are older. Some of the most common risk factors for arterial blockage include diabetes, high blood pressure and high cholesterol.
14. Carotid Artery Disease
These arteries are two blood vessels located in the neck that play an essential role in transporting blood to the brain. When plaque builds up within the carotid arteries, it can harden, narrowing the arteries. Also known as carotid artery disease, narrowed carotid arteries can result in life-threatening complications and negatively impact your health.
Without proper blood flow, parts of your brain are deprived of adequate nutrients and oxygen to function normally. In more severe cases of carotid artery disease, the plaque may even rupture and lead to a stroke or complete blockage. Without stimulation and oxygen-rich blood, the brain will begin to die. While many treatments are available for carotid artery disease, prevention is of the utmost importance to ensure good health.
15. Heart Murmur
A heart murmur is the sound of blood flow around or in the heart in addition to your heartbeat. These can occur when the heart is emptying, filling or even continuously. There are two types of heart murmurs, including abnormal and innocent heart murmur. An innocent heart murmur often occurs from common conditions that cause the heart to beat harder or faster, such as anemia, physical activity or pregnancy. Fortunately, they are normally harmless.
These are common, affecting 10% of adults and 40% to 45% of children. On the other hand, abnormal heart murmurs can indicate a serious underlying medical cause. The intense sounds of a heart murmur may occur from congenital defects, heart valve problems or an overworked heart. While abnormal murmurs are not a disease, they are commonly a sign of a more dangerous condition.
What to Expect When You Visit a Cardiologist

The cardiologists at Modern Heart and Vascular Institute in Texas treat each patient individually and customize all treatments to fit their unique needs. We pride ourselves on taking a human-centric approach to each patient to provide the highest level of care possible. Our heart doctors in Texas are equipped with the latest diagnostic tools to detect and diagnose cardiac conditions effectively. When you visit Modern Heart and Vascular Institute, you can expect:
- Cardiovascular exams: If it is your first appointment with a new cardiologist, you will likely be asked general questions about your overall health and more specific questions about why you are visiting a cardiologist. A cardiologist may ask you specific questions about any symptoms you may be experiencing. The cardiologist will also perform a physical examination to assess your health. In some cases, a cardiologist may recommend additional testing to diagnose a heart condition.
- Additional testing: Additional cardiac testing can help cardiologists diagnose any potential health conditions. Depending on your symptoms, your cardiologist may order an electrocardiogram, echocardiogram, cardiac CT scan, and nuclear stress tests. Other common tests include a Doppler ultrasound, ankle-brachial index and cardiac PET/CT scans.
- Treatments: If your cardiologist diagnoses a cardiac condition, there are many potential treatments available. One of the most important steps is preventive heart care, which can greatly reduce the likelihood of a patient developing a cardiac disease. In some cases, a cardiologist may recommend a pacemaker, modern vein treatments, or enhanced external counterpulsation.
- Follow-up appointments: In many cases, patients may need to schedule follow-up appointments with a cardiologist. Additional appointments help to monitor a patient’s overall health and heart health. Routine appointments can also monitor if a treatment is effective or improving symptoms of a heart condition. Many patients also schedule follow-up appointments with cardiologists following heart surgery.
Book an Appointment Today
Modern Heart and Vascular Institute heart doctors in Humble, Texas, Katy, Texas and Cleveland, Texas, focus on preventing unnecessary procedures and surgeries. We pride ourselves on offering innovative, state-of-the-art diagnostic exams and tools to assess the heart and diagnose any underlying conditions.
Our providers specialize in all aspects of metabolic and cardiovascular diseases. We use the latest imaging and non-imaging modalities to provide the highest level of care to all patients. We treat each patient individually and strive to provide customized care. We also offer same-day appointments to best suit your schedule and needs. If you’d like to learn more about our practice, read our providers’ bios.
To learn more and schedule an appointment, contact us online today or call 832-644-8930.
This article does not provide medical advice. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. If you need cardiovascular care, please call us at 832-644-8930.