In the twenty-first century heart disease is the leading cause of death in many developed countries around the world, including the USA and the UK. There are many different types of heart disease, including ischemic, rheumatic, and congestive. By far the most commonly encountered is coronary heart disease.


The symptoms of coronary heart disease include shortness of breath during times of stress or exercise, heart palpitations, and pain in the chest area, known as angina. At this stage the condition is usually manageable, however if left untreated the damage to the heart will eventually lead to the occurrence of coronary failure, otherwise known as a heart attack.


Heart disease essentially stops the heart from functioning correctly. When fatty substances build up in the coronary arteries the blood vessels become very narrow. As a result, the blood flow is restricted, which in turn starves the heart of the oxygen it requires. Over time the muscles of the heart weaken and deteriorate due to this lack of blood and oxygen, which triggers a heart attack. With advances in modern medicine it is possible to survive, and make a full recovery from, a heart attack, however on many occasions they are so severe that they prove to be fatal.


It is no coincidence that heart disease is so common in modern society, where people work long hours in stressful jobs, and fatty foods are in abundance. Stress and diet are known to be two of the main contributing factors to the development of the condition. When people feel stressed they produce the hormone cortisol, which increases the likelihood of them having hardened calcium deposits in their arteries. Moreover, they are less likely to take the time to eat healthily.


Diet is extremely important when determining a person's risk of heart disease. Foods which are high in saturated fats increase LDL cholesterol in the body, which contributes to a narrowing of the heart's arteries. In addition, the fatty content of these foods can lead to obesity and high blood pressure. When a person is overweight the heart has to work much harder to pump blood around the body, and this extra strain can often lead to heart failure.


Another factor which affects the heart's ability to function correctly is smoking. The nicotine found in cigarettes is a stimulant, which means that it forces the heart to work harder than it would naturally. Furthermore, the inhalation of cigarette smoke restricts the flow of oxygen to the heart, thereby straining it even more. Numerous tests have found that smokers are at an increased risk of  heart disease.


Other factors which should be taken into consideration are age, gender, family history, and ethnicity. It is generally the case that older people tend to suffer from heart disease more than the younger generations, as the condition develops gradually over time. Although men are more likely to suffer from heart disease, women are also at risk, particularly if they are overweight smokers. However, pre-menopausal women are less at risk, as their bodies produce the hormone oestrogen. This hormone protects the heart naturally against disease. Regardless of gender, a family history of heart disease will increase a person's chances of developing the condition. Finally, research has shown that some ethnic groups may be more prone to heart disease than others.


The seriousness and prevalence of heart disease means that it is important to take steps to maintain a healthy heart. Diet is key, with fruit, vegetables, and whole grains preferable to salt, sugars, and fats. Exercising regularly is extremely important, as it will not only strengthen the heart muscles, but will also help to de-stress and to control weight. It is also essential to avoid tobacco products. Finally, reducing the risk of heart disease involves monitoring the heart's effectiveness with regular medical check-ups for cholesterol, blood pressure, blood sugar levels, and body mass index.