Communicable, non-communicable diseases, accidents, and injuries have been identified as the top causes of death worldwide. World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) have narrowed down the causes of mortality rate fluctuations.

Centers for Disease Control and Prevention (CDC) have narrowed down the list of the leading causes of death in the year 2015 particularly in United Sates. The list includes; heart disease, cancer, chronic lower respiratory diseases, accidents (unintentional injuries), stroke (cerebrovascular diseases), Alzheimer's disease, Diabetes, Influenza, Pneumonia, Nerve diseases, and intentional self-harm (sucide cases).

On the other hand, the World Health Organization (WHO) has categorized the leading causes of death by economy income group. 52 percent of all deaths in low income countries in 2015 were caused by "Group I" conditions. These includes; communicable diseases, maternal causes, nutritional deficiencies, and underlying conditions during pregnancy and childbirth. 7 percent deaths are coming from the high income countries. Altogether, lower respiratory infections have been the leading cause or mortality in both high income and low income countries.

Non-communicable Diseases (NCD) caused almost 70 percent deaths globally derived from 37 percent of low income countries and 88 percent of high income countries. Moreover, the NCD absolute number of death globally was about 78 percent coming from the different social stratifications.

Lastly, the injuries were the culprit of almost 5 million lives in 2015. Low income countries had the highest mortality rate because of road traffic injuries. Road injuries were also the leading causes of death from the different social stratifications.  

The top causes of death from low income economies in 2015 include; lower respiratory infections, diarrheal conditions, stroke, ischemic heart disease, HIV/AIDS and tuberculosis. Middle income economies includes; ischemic heart disease, stroke, lower respiratory infections, COPD, tuberculosis, and diarrheal diseases. An upper income economy includes; ischemic heart disease, stroke, COPD, Trachea bronchus lung cancers, lower respiratory infections and diarrheal diseases.     

Low income system and economy has a higher percentage of mortality rates because of poverty and low development in both healthcare and facilities. The cause of death rates can help in developing new treatment approach to the different disease conditions that commonly tops the list.