Health and disease

• Coronary heart disease (CHD) is a non-communicable disease where fatty material builds up inside the coronary arteries
• Fatty deposits in the coronary arteries are mainly formed from cholesterol from dietary sources and synthesized by the liver
• Buildup of plaque in the coronary arteries narrows the lumen, reducing blood flow to the heart
• Partial blockage of coronary arteries leads to restricted blood flow and severe chest pains called angina
• Complete blockage of coronary arteries can result in a heart attack
• Treatment of CHD involves using stents to widen the lumen of coronary arteries or prescribing statins to lower blood cholesterol levels
• Stents are effective at reducing the risk of heart attacks by increasing blood flow in the coronary arteries
• Statins are drugs that reduce fatty deposits in the blood by blocking an enzyme in the liver
• Faulty heart valves can be replaced via surgery using biological valves from cows or pigs, or mechanical valves
• Heart transplants can be done in cases of heart failure, with artificial hearts used as a short-term solution while waiting for a donor heart
• Artificial hearts have advantages such as shorter wait times and lower rejection rates, but they may not pump blood as effectively as real hearts and have an increased risk of blood clots
• The heart is made of cardiac muscle cells that require a supply of blood to deliver oxygen, glucose, and other nutrients and remove waste products like carbon dioxide
• The blood is supplied to the heart by the coronary arteries branching off directly from the aorta
• It is vital for the heart to constantly respire, so it needs to receive oxygen
• Stents can be used to keep the coronary arteries open
• Procedure for inserting a stent:

  • A narrow tube is threaded up through the groin up to the blocked vessel
  • A tiny balloon is inflated
  • The balloon pushes the metal or plastic stent against the wall of the artery, increasing the width of the lumen
  • The balloon and tube are then removed
• Advantages of statins:

  • Reduces the amount of 'bad' cholesterol in your blood, reducing the risk of strokes, coronary heart disease, and heart attacks
  • Increases the amount of 'good' cholesterol in your blood, aiding in the removal of 'bad' cholesterol
  • May help prevent other diseases
• Disadvantages of statins:

  • Statins are a long-term drug
  • Requires regular intake
  • Can cause negative side effects
  • The effects of statins are not instant and take a while to work
• Health is the state of physical and mental well-being; it can be influenced by various factors
• Diseases, both communicable and non-communicable, are major causes of ill health
• Ill health can lead to a poorer quality of life or reduced lifespan
• The cost of being ill includes the inability to work and the need for expensive healthcare
• Communicable diseases are caused by pathogens and can spread between individuals or individuals and animals
• Examples include chickenpox caused by the varicella-zoster virus and Covid-19 caused by the SARS-CoV-2 virus
• Non-communicable diseases are not caused by pathogens and have longer-lasting effects
• Examples include asthma, CHD, and most cancers
• Factors like diet, stress, and life situations can profoundly affect physical and mental health
• Eating a balanced diet maintains good health, while a poor diet can lead to deficiencies, obesity, diabetes, and poor mental health
• Chronic stress can lead to cardiovascular issues and poor mental health
• Where a person lives and their income can impact their health and access to healthcare
• Different types of diseases may interact negatively affecting an individual's health
• Defects in the immune system increase susceptibility to infectious diseases
• Viruses in cells can trigger cancers, like HPV causing cervical cancer and hepatitis virus causing liver cancer
• Immune reactions to pathogens can trigger allergies like skin rashes and asthma
• Severe physical ill health can lead to depression and other mental illnesses, impacting the immune system and lifestyle choices
• Risk factors are linked to an increased rate of a disease, but exposure to a risk factor doesn't guarantee that an individual will suffer from the disease
• Certain risk factors correlate with certain diseases, but correlations are not always causations
• Risk factors can be:

  • Aspects of a person's lifestyle, such as the food they eat or whether or not they drink alcohol
  • Substances in the person's body or environment, such as air pollution in a crowded city or asbestos in old buildings
• Risk factors for cardiovascular disease:

  • Diet, smoking, and exercise have a causal relationship with cardiovascular disease
• Risk factors for Type 2 Diabetes:

  • Obesity has a causal relationship with Type 2 Diabetes