Epidemiological transition refers to the shift in a country's health profile from infectious or contagious communicable diseases (epidemics) to non-communicable diseases that cause gradual health deterioration (degenerative diseases). Think of it like a country moving from battling colds and the flu to facing issues like heart disease or diabetes.

For instance, in a developing country, you might find illnesses like respiratory diseases, measles, and gastroenteritis (stomach issues causing vomiting and diarrhea). In developed countries, like the U.S. or the U.K., heart attacks, strokes, and cancers are more common.

Real World Example: Ever since the 1980s, even developed countries have seen a surge in AIDS cases which is an infectious disease. It's like the rules of the game changed midway!

This study examined 240 diseases in 72 countries and found that life expectancy increased from 65.3 years in 1990 to 71.5 years in 2013. While this is good news, the number of deaths also increased from 47.5 million to 54.9 million. This is kind of like celebrating your favorite football team scoring a goal, but then realizing the opposing team scored two!

Interestingly, there were fewer deaths due to cardiovascular diseases and cancers in high-income regions, and fewer child deaths from diarrhoea, lower respiratory infections, and neonatal causes in low-income regions. On the flip side, HIV/AIDS reduced life expectancy in southern sub-Saharan Africa.

Real World Example: Even though more people are living longer, the causes of death have shifted from infectious diseases to lifestyle diseases, particularly in developed countries.

It's important to note that death rates can vary widely between countries and regions. It's not a one-size-fits-all scenario! The U.S. saw a significant reduction in mortality rates in males aged 5-9 years, but an increase in mortality rates in females over 70 years. Meanwhile, in China, females aged 28-36 years experienced the most significant reduction in mortality rates.

Real World Example: The main causes of death in the U.S. were heart disease, lung cancer, and Alzheimer’s, linked to poor diet, obesity, and smoking. In China, the main causes were stroke, heart disease, and road injuries, linked to poor diet, high blood pressure, and air pollution. In Afghanistan, lower respiratory infection, preterm birth, and congenital anomalies were the main causes, linked to malnutrition, air pollution, and poor diet.