Non-infectious or non-communicable diseases are caused by malfunctions of the body. These include organ or tissue degeneration, erratic cell growth, and faulty blood formation and flow. Also included are disturbances of the stomach and intestine, the endocrine system. Some diseases can be caused by diet deficiencies, lapses in the body’s defense system, or a poorly operating nervous system.
Noncommunicable diseases (NCDs) include cardiovascular, renal, nervous, and mental diseases, musculo-skeletal conditions such as Arthritis and allied diseases, chronic non-specific respiratory diseases such as Chronic Bronchitis, Emphysema, and Asthma.
Furthermore non-communicable diseases include permanent results of accidents, senility, blindness, cancer, diabetes, obesity, and various other metabolic and degenerative diseases and chronic results of communicable diseases.
Deficiency diseases also part of non-communicable diseases are due to deficiency in the diet of a nutrient and they can be generally cured by providing the missing nutrients.
Degenerative diseases occur due to malfunctioning of some organ or organ system in the body. The incidence and prevalence of degenerative diseases in non-communicable diseases is observed to be growing alarmingly. This transition is principally due to a combination of demographic and lifestyle
changes which result from socio-economic development.
In non-infectious disease, the whole complex of environmental factors and biological responses (inborn and acquired) must be considered to account for regional variation. The fact that Negroes are more susceptible to frostbite than Eskimos or North American Indians may be attributed to both lack of acclimatisation and genetic susceptibility. Many diseases have been accorded a ‘racial pathology’ but the distribution was entirely related to environmental peculiarities. Primary cancer of the liver, common among Africans seems to be a sequel of the widely prevalent liver cirrhosis. It is caused by consumption of diet chronically low in animal protein and rich in carbohydrate since infancy. Striking ‘racial’ differences in the incidence of coronary disease is associated with diets high in fat.
Many diseases and malformations are known to have genetic basis; the afflicted individual is usually homozygous for the recessive gene, though dominant genes are also involved in some conditions. Genetic diseases are very rare. However, certain populations have high frequency of such diseases. Thalassemia and sicklecell anemia are haemoglobin variants caused by mutation in hemoglobin gene. Haemolytic disease of the new-born due to rhesus incompatibility is characteristic of European but not of most Mongoloid or Amerindian populations, since they are devoid of Rh-negative individuals. There is an increased risk of duodenal ulcers in individuals of blood group O and individuals with blood group A are more prone to stomach cancer than others.
Four main diseases are generally considered to be dominant in NCD mortality and morbidity: cardiovascular diseases (including heart disease and stroke), diabetes, cancer and chronic respiratory diseases (including chronic obstructive pulmonary disease and asthma):
- Cancer
- Cardiovascular Disease
- Chronic Respiratory Disease
- Diabetes
In addition to these 4 main diseases, mental disorders are considered to be major contributors to the economic losses stemming from NCDs. Vigo et al describe Five types of mental illness (major depressive disorder, anxiety disorders, schizophrenia, dysthymia, bipolar disorder) that appeared in the top 20 causes of global burden of disease (GBD) in 2013 and argue that the global burden of mental illness is underestimated due to the following five issues:
- The overlap between psychiatric and neurological disorders
- The grouping of suicide and behaviours associated with self-injury as a separate category outside the boundary of mental illness
- The conflation of all chronic pain syndromes with musculoskeletal disorders
- The exclusion of personality disorders in mental illness disease burden calculations
- Inadequate consideration of the contribution of severe mental illness to mortality from associated causes
NCD Risk Factors
These disease groups are linked by common risk factors:
- Social Determinants of Health (this is the environment in which we are born, live and grow and the opportunities we are given in those environments)
- Tobacco
- Alcohol
- Poor Nutrition
- Physical Inactivity
Non-modifiable Risk Factors refer to characteristics that cannot be changed by an individual (or the environment) and include age, sex, and genetic make-up. Although they cannot be the primary targets of interventions, they remain important factors since they affect and partly determine the effectiveness of many prevention and treatment approaches.
Modifiable Risk Factors refer to characteristics that societies or individuals can change to improve health outcomes. WHO typically refers to four major ones for NCDs: poor diet, physical inactivity, tobacco use, and harmful alcohol use.
The Global status report on noncommunicable diseases 2010 reports that contrary to popular opinion, available data demonstrate that nearly 80% of Non-Communicable Disease (NCD) deaths occur in low and middle-income countries. NCDs are caused, to a large extent, by four behavioural risk factors that are pervasive aspects of economic transition, rapid urbanisation and 21st-century lifestyles: tobacco use, unhealthy diet, insufficient physical activity and the harmful use of alcohol. The greatest effects of these risk factors fall increasingly on low and middle-income countries, and on poorer people within all countries, mirroring the underlying socioeconomic determinants. Among these populations, a vicious cycle may ensue: poverty exposes people to behavioural risk factors for NCDs and, in turn, the resulting NCDs may become an important driver to the downward spiral that leads families towards poverty.
Efforts to Combat NCDs
The United Nations (UN) and the World Health Organisation (WHO) have called for a 25% reduction by 2025 in mortality from NCDs, adopting the slogan “25 by 25.” Hunter in his article summarising NCDs argues that in order to reach this goal the following treatments must be addressed:
- Disease Burden
- Economic Effects
- Prevalence of Risk Factors
- Infectious Diseases, Malnutrition, and other diseases of poverty that contribute to NCDs
The Global Status Report on Non-Communicable Disease 2014 is the second in a triennial series tracking worldwide progress in prevention and control of NCDs. The most important message of the second global report on NCDs is that, today, the global community has the chance to change the course of the NCD epidemic.
The Global Action Plan for the Prevention and Control of NCDs 2013-2020 provides a road map and a menu of policy options for all Member States and other stakeholders, to take coordinated and coherent action, at all levels, local to global, to attain the nine voluntary global targets, including that of a 25% relative reduction in premature mortality from cardiovascular diseases, cancer, diabetes or chronic respiratory diseases by 2025. The main focus of this action plan is on the four major NCDs, “Cardiovascular Disease, Cancer, Chronic Respiratory Disease and Diabetes”, but also highlight the four shared behavioural risk factors, “Tobacco Use, Unhealthy Diet, Physical Inactivity and Harmful use of Alcohol”.