Demographic Transition Model (DTM): Changes in the birth rate and death rate in a country are shaped by how a country changes from an agrarian to an industrial society. The UK is a stage 4 country. The birth and death rates are low fluctuating, but the population is high. This model displays the change through time and how the population changes within the UK. There are many reasons for the population change in the UK. For example, in the 1900s the birth rate dropped dramatically due to World Wars 1 and 2. Between the late 1700s and 1800s nutrition improved which caused in infant mortality rates to drop. There are many factors that impact the UK's DMT level. Some of those include having an ample healthcare system, highly literate and educated citizens, and expanded employment opportunities for women.
The Epidemiological Transition: Epidemiology is the branch of medicine that deals with the "incidence, distribution, and possible control of diseases related to health." The UK is in stage 4 of the epidemiological transition. This means some factors they face include delayed degenerative diseases, low but increasing death rate, increasing life expectancy, and low rate of natural increase.