Disease

According to the World Health Organisation (WHO), there were 56.4 million deaths recorded in 2015. The top ten causes of death were:

Cause of Death	Millions	Percentage
Ischaemic heart disease	8.76	15.53
Stroke	6.24	11.06
Lower respiratory infections	3.19	5.66
Chronic obstructive pulmonary disease	3.17	5.62
Trachea, bronchus, lung cancers	1.69	3
Diabetes mellitus	1.59	2.81
Alzheimers disease	1.54	2.73
Diarrhoeal diseases	1.39	2.46
Tuberculosis	1.37	2.43
Road injury	1.34	2.37

In 2000, the top four causes were in the same order, but look at the rest (percentages based on total deaths recorded at 52.1 million)

Cause of Death	Millions	Percentage
Ischaemic heart disease	6.88	13.21
Stroke	5.41	10.38
Lower respiratory infections	3.41	6.55
Chronic obstructive pulmonary disease	2.95	5.66
Diarrhoeal diseases	2.18	4.18
Tuberculosis	1.67	3.21
HIV/AIDS	1.46	2.8
Preterm birth complications	1.34	2.57
Trachea, bronchus, lung cancers	1.26	2.42
Birth asphyxia and birth trauma	1.12	2.15

In 2000 in these records, 52.1 million people died. In 2015, 56.4 million. At first glance, that looks like more people died in 2015, but let’s factor in the population of the Earth in those years:

Year	Population	Deaths	Percent Deaths
2000	6.1 billion	52.1 million	0.854%
2015	7.2 billion	56.4 million	0.783%

So in 2015, an extra 0.07% survived that would otherwise have died. In today’s terms, that’s 5 million (0.07% of 7.2 billion) people alive today thanks to improvements in healthcare, along with other contributing factors.

Of course, it’s more complicated than that, but generally, we are starting to figure out ways to cheat death.

The two main killers are ischaemic heart disease and stroke. The fact that the percentage of incidence increased in those two does not mean we have a plague of heart attacks and strokes suddenly appearing. Instead, it means that the diseases that people would normally have died of in earlier years are being so successfully managed that those people are living long enough to die of diseases normally reserved for older people. In a very real sense, this is a good thing.

The top ten list changes year by year as we discover how to reduce the danger posed by various risks.

In this chapter, I’ll talk about how the list has changed over the last 15 years.

I will show a number of graphs in the chapter to illustrate how mortality is changing over time. I will restrict the data to developed countries (specifically, I'll use Ireland because that's where I am), and will keep the data restricted to cover people aged 30-49 (because I'm right in the middle, and I expect you are probably as well). The source for the data is the World Health Organisation.

As an example, here is the top table, graphed with just the data for Irish people aged 30-49, between the years 2000-2015:

The trend is downwards.

I chose Ireland deliberately because that's where I am, but the same trend can be seen right across the developed world.

In less developed countries, there are not always improvements, but in general, the world itself is improving.