The cardiovascular system, also called the circulatory system, is the system that moves blood throughout the human body. It is composed of the heart, arteries, veins, and capillaries. It transports oxygenated blood from the lungs and heart throughout the whole body through the arteries. Blood goes through the capillaries - vessels situated between the veins and arteries.
When the blood has been depleted of oxygen, it makes its way back to the heart and lungs through the veins.
The circulatory system may also include the circulation of lymph, which is essentially recycled blood plasma after it has been filtered from the blood cells and returned to the lymphatic system. The cardiovascular system does not include the lymphatic system. In this article, the circulatory system does not include the circulation of lymph.
The human circulatory system (anterior view)
Examples of diseases that affect the cardiovascular system
- Cardiac diseases (Heart diseases) - examples include:
- Angina (considered as both a cardiac and vascular disease)
- Arrhythmia (problems with the heartbeat, irregular heartbeat)
- Congenital heart disease
- Coronary artery disease (CAD)
- Dilated cardiomyopathy
- Heart attack (myocardial infarction)
- Heart failure
- Hypertrophic cardiomyopathy
- Mitral regurgitation
- Mitral valve prolapse
- Pulmonary stenosis
- Vascular diseases (diseases that affect the blood vessels - arteries, veins or capillaries), examples include:
- Peripheral artery (arterial) disease
- Renal artery disease
- Raynaud's disease (Raynaud's phenomenon)
- Buerger's disease
- Peripheral venous disease
- Stroke - known as a type of cerebrovascular disease
- Venous blood clots
- Bloodclotting disorders.
What are the risk factor for cardiovascular disease?A risk factor is something that increases your chances of developing a disease, disorder or condition. Obesity is a risk factor for type 2 diabetes
Researchers from the Northwestern University Feinberg School of Medicine reported in JAMA that the lifetime risk for cardiovascular disease is more than 50% for both men and women. They added that even among those with few or no cardiovascular risk factors, the risk is still more than 30%.
According to the National Health Service (NHS), UK, there are nine main risk factors associated with cardiovascular disease, they are:
- Hypertension (high blood pressure) - this is the one major risk factor for CVD by far. If hypertension is poorly controlled, the artery walls may become damaged, raising the risk of developing a blood clot
- Radiation therapy - scientists from the Karolinska Institutet, Sweden, reported in the Journal of the American College of Cardiology that radiation therapy can increase the risk of cardiovascular disease later in life.
- Smoking - regular smoking can narrow the blood vessels, especially the coronary arteries.
- Lack of sleep - people who sleep less than 7.5 hours each day have a higher risk of developing cardiovascular disease, researchers from Jichi Medical University, Tochigi, Japan, reported in Archives of Internal Medicine.
- Hyperlipidemia (high blood cholesterol) - there is a higher chance of narrowing of the blood vessels and blood clots
- Having a partner with cancer - a person whose partner has cancer has a nearly 30% higher risk of developing stroke or coronary heart disease, investigators from the Centre for Primary Healthcare Research in Malmö, Sweden, revealed in the journal Circulation.
- Diabetes - this includes both types 1 and 2. High blood sugar levels can harm the arteries. People with type 2 diabetes are often overweight or obese, which are also risk factors for cardiovascular disease. People with diabetes are 2 to 4 times more likely to die from heart disease than non-diabetics.
Experts say that blood glucose control measurements can help predict a diabetes patient's cardiovascular disease risk.
- Unhealthy eating - diets which are high in fat combined with carbohydrates, especially if they consist mainly of fast foods, can accelerate the accumulation of fatty deposits inside the arteries, which raise the risk of obesity, hypertension and hyperlipidemia. Diets which lack adequate amounts of fruit, vegetables, fiber, whole grains and essential nutrients are not good for cardiovascular health.
A study published in BMC Medicine (March 2013 issue) found that consuming processed meat is associated with developing cardiovascular disease and cancer.
Is reduced salt intake linked to the fall in deaths from cardiovascular disease? - Between 2003 and 2011, average salt intake fell by 15% in England, and deaths from heart disease and stroke fell by around 40%. A research team from Queen Mary University of London investigated the connection and their research was published in BMJ in April 2014.
High sodium intake 'causes 1 in 10 global cardiovascular deaths each year' - The World Health Organization recommend that adults should consume less than 2 g of sodium per day. But a new study finds that sodium intake above this recommendation accounts for almost 1 in 10 cardiovascular deaths globally each year.
- Physical inactivity - people who lead predominantly sedentary lives tend to have higher blood pressure, more stress hormones, higher blood cholesterol levels, and are more likely to be overweight. These are all risk factors for cardiovascular diseases.
- Drinking too much alcohol - people who drink too much tend to have higher blood pressure and blood cholesterol levels.
- Stress - hormones associated with (mental) stress, such as cortisone, raise blood sugar levels. Stress is also linked to higher blood pressure.
- Air pollution - Belgian researchers reported in The Lancet that air pollution causes about the same number of heart attacks as other individual risk factors. The investigators assessed 36 separate studies that focused on air pollution.
- COPD and reduced lung function - a study presented at the European Respiratory Society's Annual Congress in Amsterdam, showed that people with COPD (chronic obstructive pulmonary disease) have a significant risk of developing cardiovascular disease. The researchers, from the Sunderby Hospital in Sweden, added that patients with reduced lung function are also at higher risk.
- The age of first menstruation - females who start menstruating early are more likely to become obese, and have cardiovascular disease risk factors, researchers reported in the Journal of Clinical Endocrinology & Metabolism.
Experts agree that the most common risk factors for cardiovascular disease are atherosclerosis and/or hypertension.
Recent developments on cardiovascular disease causes from MNT news
A new study investigating links between depression and heart disease has found that women aged 55 and younger are more than twice as likely to suffer from major cardiac problems if they have moderate or severe depression.
These cardiac problems include death from heart disease, heart attacks and requiring an artery-opening procedure.
A combination of smoking and giving birth preterm can more than triple the risk of cardiovascular disease faced by mothers, according to the findings of a new study published in the European Journal of Preventive Cardiology.
Poor diet has a clear impact on human health, and what nourishes people as children, and even in the womb, can affect them in later life. New research suggests that lack of oxygen in the womb, combined with high salt intake in later life, can lead to vascular problems.
What is the health burden of cardiovascular disease worldwide?According to WHO (World Health Organization):
- Cardiovascular diseases (CVDs) are the leading cause of deaths globally - more people die from CVDs than anything else
- In 2008, approximately 17.3 million people died from CVDs worldwide; just under one third (30%) of all registered premature deaths. Of these deaths:
- 7.3 million died from coronary heart disease
- 6.2 million from stroke
- The majority (80%) of CVD deaths occur in low and middle-income countries
- CVDs occur equally in men and women
- Twenty-five million people will die from CVDs annually by 2030 - most of the deaths being due to stroke and heart disease.
- The majority of CVDs are preventable if people addressed their risk factors
- Hypertension (raised blood pressure) is responsible for 7.5 million deaths each year
Cardiovascular disease prevention in adultsReducing your risk of developing cardiovascular disease involves addressing the risk factors listed above, i.e. eating a healthy diet, doing plenty of exercise, achieving a healthy body weight and then maintaining it, and not smoking.
For people with cardiovascular disease, cocoa flavanols may be a vital part of a healthy diet, researchers from the University of California San Francisco reported in the Journal of the American College of Cardiology (JACC).
If you drink alcohol, do not exceed the recommended daily limits of 2 to 3 units per day for women and 3 to 4 for men.
Eating fresh fruit every day 'could reduce risk of CVD by up to 40%'. The research team, led by Dr. Huaidong Du from the University of Oxford in the UK, presented the findings of their study at the European Society of Cardiology Congress 2014.
Cardiovascular disease prevention in childrenResearch has shown that lesions can appear in the aortas and right coronary arteries of children as young as 7 to 9 years of age.
Bad habits during childhood will not lead to cardiovascular disease while the person is a child, but a trend sets in that establishes the accumulation of problems that continue into adulthood, resulting in a much greater probability of having a cardiovascular disease later in life.
Children who eat a lot of salt have a much higher risk of hypertension when they are adults, as well as heart disease and stroke. Parents should also keep a close eye on how much saturated fat and sugar a child consumes.
A child, if given the right environment, is naturally physically active. In our modern society, kids spend a great deal of time watching TV, playing video games, and being chauffeured around by their parents. Something their grandparent rarely or never did when they were small.
UK health authorities say that children aged five or less who are able to walk unaided should be physically active for at least three hours each day - these hours should be spread out.
Children aged from 5 to 18 years should do at least one hour of aerobic activity daily - their activities should include a range of intensities, from the equivalent of fast-walking to running.
Swedish scientists reported that healthy children can start to show a greater risk of future heart problems if they are physically inactive.
Recent developments on cardiovascular disease prevention from MNT news
Researchers have found that men whose low levels of testosterone were treated with testosterone replacement therapy also experienced a reduced risk of heart attack, stroke and all-cause mortality.
A new clinical perspective from the Journal of the American College of Cardiology confirms that most people in developed countries should be more concerned with the lack of exercise in their lives than by the potential harm exercise can cause.
New research provides further evidence of the health benefits of fruit consumption, after finding that eating fresh fruits daily may lower the risks of heart attack, stroke and cardiovascular death.
Does aspirin protect from cardiovascular disease?Aspirin, also known as acetylsalicylic acid (ASA) is a medication that is generally used as an analgesic (painkiller that does not produce anesthesia or loss of consciousness) for minor pains; it is also used as an antipyretic (to reduce fever) and as an anti-inflammatory.
Aspirin has also become more and more popular as an antiplatelet - to prevent blood-clot formation. High-risk patients take it in low doses to prevent strokes and heart attacks.
Aspirin is also given to patients after a heart attack to prevent cardiac tissue death or heart attack recurrence.
A major problem posed by aspirin therapy for patients at risk of heart attack, stroke and other cardiovascular events is major bleeding. A considerable proportion of patients with diabetes have a high rate of major bleeding, regardless of their therapeutic aspirin status.
There have been literally hundreds of studies on the benefits, harms and inefficacy of aspirin over the last twenty years. While some have shown benefits for the cardiovascular system, especially among patients with existing conditions, others have concluded that healthy people should not take regular low-dose aspirin.
Below are links to some studies on the benefits and harms of aspirin for reducing the risk of cardiovascular diseases and events:
- "An aspirin a day will keep heart attack away"
- "Use of low dose aspirin to protect against cardiovascular disease should be abandoned"
- "For healthy people daily aspirin may do more harm than good"
- "For patients with type 2 diabetes in Japan, taking low-dose aspirin does not significantly reduce cardiovascular risk"
- "Aspirin only benefits diabetics with history of heart disease or stroke"
- "Women taking daily aspirin have lower death risks says new study"
- "For most heart failure patients, aspirin and warfarin equally effective"