health and disease

• diseases are a major cause of...

  ill health
• what is health?


  a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity
• physical health


  relates to the efficient functioning of the body and its systems, and includes the physical capacity to perform tasks and physical fitness.
• social health


  being able to interact with others and participate in the community in both an independent and cooperative way
• mental health


  the state of mental well-being in which one can cope with the demands of daily life with regard to their psychological and emotional well-being
• diseases can be ... or ...

  communicable, non-communicable
• what are communicable diseases?

  diseases that can be spread from person to person or between animals and people. they can be described as contagious or infectious.
• what are communicable diseases caused by?

  they can be caused by bacteria, viruses, protists and/or fungi
• examples of communicable diseases

  pneumonia, HIV/AIDS, tuberculosis (TB), malaria, measles, STDs
• communicable diseases can...


  spread
• what are non-communicable diseases?


  diseases that cannot be spread between people or between animals and people. they generally last for a long time and get worse slowly
• what are non-communicable diseases caused by?

  caused by lifestyle (risk) factors and genetics - not pathogens
• examples of non-communicable diseases

  asthma, cancer, coronary heart disease, diabetes
• non-communicable diseases can...


  not spread
• different types of disease sometimes...

  interact and cause other physical and mental health issues that don't immediately seem related
• people who have problems with their immune system have an increased chance of...

  suffering from communicable disease such as influenza (flu), because their body is less likely to be able to defend itself against the pathogen that causes disease
• some types of cancer can be triggered by...

  infection by certain viruses (e.g. some types of hepatitis virus can cause long-term infections in the liver, where the virus lives in the cell, which can lead to an increased chance of developing liver cancer. HPV (human papilloma virus) can cause cervical cancer in women)
• immune system reactions in the body caused by infection by a pathogen can sometimes trigger...

  allergic reactions such as skin rashes or worsen symptoms of asthma
• mental health issues such as depression can be triggered when...

  someone is suffering from severe physical health problems, particularly if they have an impact on the person's ability to carry out everyday activities or if they affect the person's life expectancy
• what factors can affect your health?

  - balanced diet: provides your body with everything it needs

  - stress: being constantly under lots of stress can lead to health issues

  - life situation: having easy access to medicine or things that can prevent illness e.g. buy healthy food or condoms to prevent the transmission of an STD
• human cost of non-communicable diseases

  - death

  - lower quality of life or shorter lifespan

  - affects loved ones
• financial cost of communicable diseases

  - research cost is huge

  - families may have adapt their home to move somewhere better suited to help sick family member

  - if the sick family member has to give up work or dies, the family income would be reduced: this also affects the country's economy
• risk factors increase your chance of...

  getting a disease
• what are risk factors?

  things that are linked to an increase in your chance of contracting a disease
• lifestyle risk factor


  the way a person lives & works can put them at risk for some diseases
• environment risk factor


  all the external physical, chemical, biological, and work-related factors that affect a person's health
• what do risk factors depend on?

  characteristics at the biological, psychological, family, community, or cultural level
• some risk factors can cause ... directly

  disease
• what has smoking been proven to directly cause?

  cardiovascular disease, lung disease and lung cancer

  - it damages the walls of arteries and the cells in the lining of the lungs
• what is obesity thought to directly cause?

  type 2 diabetes

  - by making the body less sensitive or resistant to insulin, meaning that it struggles to control the concentration of glucose in the blood
• what does drinking alcohol directly link to?

  liver disease

  - though the liver breaks down alcohol, the reaction can damage its cells

  - liver cells may also be damaged when toxic chemicals leak from the gut due to the intestines caused by alcohol

  
  

  brain damage

  - too much alcohol can affect the brain function too. it can damage the nerve cells in the brain, causing the brain to lose volume
• what does alcohol do to an unborn baby?

  alcohol can damage the baby's cells, affecting its development and causing a wide range of health issues
• what does smoking cause?

  disease of the heart, blood vessels and lungs and cancer
• what does smoking do to an unborn baby?

  smoking while pregnant reduces the amount of oxygen the baby receives in the womb and can cause numerous health problems for the baby
• what can cancer be directly caused by?

  exposure to certain substances or radiation. things that cause cancer are known as carcinogens
• what do carcinogens do?

  can cause mutations in a gene which tells the cell to stop dividing or divide uncontrollably
• what is cancer caused by?

  uncontrolled cell growth and division
• not all tumours are...

  cancerous
• benign tumour


  - this is where the tumour grows until there's no more room

  - the tumour stays in one place (usually within a membrane) rather than invading other tissues in the body

  - this isn't normally dangerous, and the tumour isn't cancerous
• malignant tumour


  - this is where the tumour grows and spreads to neighbouring healthy tissues

  - cells can break off and spread to other parts of the body by travelling in the bloodstream

  - the malignant cells then invade healthy tissues elsewhere in the body and form secondary tumours

  - malignant tumours are dangerous and can be fatal: they are cancerous