Non-communicable diseases
In a nutshell
Non-communicable diseases cannot be passed from one organism to another. They typically last for a long time, progress slowly and are associated with certain risk factors. There are trends in non-communicable diseases at a global, national and local level, and almost all of the trends are linked to income.
Risk factors
Definition
Risk factors are things that increase a person's chance of getting that disease. Risk factors are often aspects of a person's lifestyle. They may also be substances that are present in the environment. Sometimes, risk factors are genetic. Inheriting faulty genes does not necessarily mean you will get the disease but means you have an increased risk, especially in combination with other risk factors.
Examples
Lifestyle | How much exercise they do.
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Environment | Air pollution can contribute to asthma symptoms.
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Genetic | Inheriting particular mutated alleles increased your risk of developing coronary heart disease.
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Risk factors for cancer
Certain factors increase your risk of developing cancer.
Examples
- Poor diet
- High alcohol consumption
- Smoking
- Faulty genes
- Infections like HPV and HIV
- Ultraviolet (UV) exposure
- Radiation
Correlation and causation
Scientists identify risk factors by looking at correlations in data, but correlation doesn't always equal causation. Sometimes risk factors are linked to other risk factors and it is these other factors that actually cause the disease.
Example
A lack of exercise and a high-fat diet increases your risk of cardiovascular disease, but the disease isn't caused by these factors. It is caused by the resulting high blood pressure and high cholesterol levels.
Sometimes correlation does equal causation.
Example
Smoking, lung disease and lung cancer.
Lifestyle factors and risk of non-communicable diseases
Exercise and diet are two important lifestyle factors that affect your risk of having a non-communicable disease.
Exercise
Exercise increases the amount of energy used by the body, and decreases the amount of stored body fat. This helps to boost your metabolic rate. People who exercise are less likely to experience obesity and cardiovascular disease.
Example
A lack of exercise increases the risk of cardiovascular disease because it increases blood pressure.
Diet
Eating too much food can lead to obesity. Obesity is linked to type 2 diabetes, high blood pressure, cardiovascular disease and some cancers. Too much saturated fat in your diet can increase your blood cholesterol level. Cholesterol is an essential lipid that your body needs to function, however too much of a certain type of bad cholesterol - known as LDL cholesterol- can cause fatty deposits to form inside arteries. This can cause coronary heart disease.
Eating too little food can also cause problems. Malnutrition has different effects on the body depending on what nutrient you are missing.
Example
In children, it can lead to slow growth. In every one, malnutrition can cause fatigue, poor resistance to infection and irregular periods in females.
Deficiency diseases are caused by a lack of vitamins or minerals
Example
Scurvy is caused by a lack of vitamin C. This causes problems with the skin, joints and gums.
This is why eating enough food as part of a balanced diet is important.
Alcohol and smoking
Alcohol and smoking are two of the biggest risk factors for non-communicable diseases.
Alcohol
Alcohol is poisonous. It is broken down by enzymes in the liver and some products of this are toxic. If you drink too much alcohol over a long period of time, these toxic products can cause cells in the liver to die. This forms scar tissue and stops blood from reaching the liver. This is called liver cirrhosis.
Drinking too much alcohol increases blood pressure, which can lead to cardiovascular disease. Cancers of the mouth, throat, bowels and liver have been linked to excessive alcohol consumption. This is because the toxic products damage DNA and cause cells to divide faster than normal.
Smoking
Cigarettes contain nicotine, this is why smoking is addictive. Smoking cigarettes also produce carbon monoxide, tar and particulates. These can all cause illness and other health problems.
Examples
Health problem | Explanation
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| Cardiovascular disease
| Carbon monoxide reduces the oxygen-carrying capacity of the blood. If the cardiac muscle does not receive enough oxygen, this can lead to a heart attack. Nicotine increases the heart rate which increases blood pressure and therefore the risk of cardiovascular disease. |
| Lung, throat, mouth and oesophageal cancer | Tar from cigarette smoke is full of toxic chemicals that can cause cancer. These chemicals are known as carcinogens and they make mutations in DNA more likely. This can lead to uncontrolled cell division. |
| Lung disease(s) | Cigarette smoke can cause inflammation of the lining of the bronchi and bronchioles, resulting in permanent damage. This causes lung diseases such as chronic bronchitis, which in turn causes a persistent cough and breathing problems. |
| Smoking when pregnant | This can cause lots of health problems for the unborn baby. |
Trends in lifestyle factors
Global
Non-communicable diseases are more prevalent in developed countries where people tend to have a higher income.
| 1. | Lack of exercise and high alcohol consumption are both associated with a higher income.
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| 2. | Smoking-related deaths are more common in low-income countries. |
| 3. | In both high- and low-income countries, obesity is associated with a high income as these people are able to afford lots of high-fat food. However, this trend is changing as obesity is now associated with lower incomes as people are eating cheaper, less healthy foods. |
National
Non-communicable diseases are the biggest cause of death in the UK. However, there are regional differences across the country.
Example
People from deprived areas are more likely to smoke, have a poor diet and not take part in physical activity compared to those who have a higher income. Therefore, there is a higher incidence of heart disease, obesity, type 2 diabetes and cancers in these areas. Additionally, people from deprived areas are more likely to suffer from alcohol-related disorders.
Local
Individual lifestyle choices affect the incidence of non-communicable diseases at a local level. This means if you choose to smoke, drink, have a poor diet and not take part in exercise then the risk increases.
