Non-communicable diseases

• Risk factors increase the chance of developing a non-communicable disease, but don't guarantee it
• Examples of risk factors


  • Aspects of a person's lifestyle (e.g. exercise, diet)
  • Presence of certain substances in the environment (e.g. air pollution, asbestos)
  • Certain biological factors in the body (e.g. high blood pressure, insulin resistance)
• Some risk factors can directly cause a disease, like smoking causing cardiovascular disease and lung cancer
• Non-communicable diseases can be costly for individuals and healthcare systems
• Drinking too much alcohol has been shown to cause liver disease. Too much alcohol can affect brain function too. It can damage the cerebellum only in the brain, causing the brain to lose volume
• Smoking when pregnant can cause lots of health problems for the unborn baby. Drinking alcohol has similar effects
• Cancer can be directly caused by exposure to certain substances or radiation. Things that cause cancer are known as carcinogens. Ionizing radiation (eg from X-rays) is an example of a carcinogen
• However, risk factors are identified by scientists looking for correlations in data, and correlation doesn't always equal cause (see p.9). Some risk factors aren't capable of directly causing a disease. For example, lack of exercise and high fat diet are heavily linked to an increased chance of cardiovascular disease, but they can't cause the disease directly. It's the resulting high blood pressure and high blood cholesterol levels (see p.34) that can actually cause the disease
• The human cost of non-communicable diseases is obvious. Tens of millions of people around the world die from non-communicable diseases per year. People with these diseases may have lower quality of life or a shorter lifespan. This not only affects the sufferers themselves, but their loved ones too
• It's also important to think about the financial cost. The cost to the NHS of researching and treating these diseases is huge-and it's the same for other health services and organisations around the world. Families may have to move or adapt their home to help a family member with a disease, which can be costly. Also, if the family member with the disease has to give up work or dies, the family's income will be reduced. A reduction in the number of people able to work can also affect a country's economy
• Cancer is caused by uncontrolled cell growth and division. The uncontrolled growth and division is a result of changes that occur to the cells and results in the formation of a tumour (a mass of cells). Not all tumours are cancerous. They can be benign or malignant
• Benign tumour


  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 type isn't normally dangerous, and the tumour isn't cancerous
• Malignant tumour


  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 cancers
• Having risk factors doesn't mean that you'll definitely get cancer. It just means that you're at an increased risk of developing the disease. Cancer survival rates have increased due to medical advances such as improved treatment, being able to diagnose cancer earlier and increased screening for the disease
• Lifestyle risk factors for cancer


  • Smoking
  • Obesity
  • UV exposure
  • Viral infection
• Smoking is a well known risk factor for lung cancer, but research has also linked it to other types of cancer too, including mouth, bowel, stomach and cervical cancer
• Obesity has been linked to many different cancers, including bowel, liver and kidney cancer. It's the second biggest preventable cause of cancer after smoking
• People who are often exposed to UV radiation from the Sun have an increased chance of developing skin cancer. People who live in sunny climates and people who spend a lot of time outside are at higher risk of the disease. People who frequently use sun beds are also putting themselves at higher risk of developing skin cancer
• Infection with some viruses has been shown to increase the chances of developing certain types of cancer. For example, infection with hepatitis B and hepatitis C viruses can increase the risk of developing liver cancer. The likelihood of becoming infected with these viruses sometimes depends on lifestyle - e.g. they can be spread between people through unprotected sex or sharing needles
• Sometimes you can inherit faulty genes that make you more susceptible to cancer. For example, mutations (changes) in the BRCA genes have been linked to an increased likelihood of developing breast and ovarian cancer
• Tumours are the result of uncontrolled cell growth and division