This is the world.

Auto immune diseases are on the rise around the world.

According to the National Institutes of Health, one in 15 Americans suffer from an

autoimmune disease. In the Pacific Northwest, there is a greater prevalence of MS, irritable

bowel disease, and type 1 diabetes, all autoimmune related.

Many you will have heard of, like rheumatoid arthritis, type 1 diabetes,

an inflammatory bowel disease.

In the UK, autoimmune diseases now affect more than one in ten adults. lose hair, gain weight, and her get up and go, got up and went, she suspected something was wrong.

Talia says medical tests revealed she suffered from Hashimoto's, an autoimmune disease that

attacks her thyroid. And curiously, some have begun to turn up in countries that have never reported cases before.

So what's behind the rising cases and could our modern lifestyle potentially be to blame?

From the Guardian I'm Een Sample, and this is Science Weekly. To understand why autoimmune diseases are becoming more common around the world,

I spoke to James Lee, a clinical science group leader at the Francis Crick Institute,

and a consultant gastrointestinal enterologist at the Royal Free Hospital in London.

James, could you explain for us what an autoimmune disease actually is?

An autoimmune disease is a chronic, usually lifelong condition and the way I like to try to explain it to my patients when I'm seeing

them in clinic is that essentially your immune system has got its wires crossed so

that instead of fighting off coughs and colds and keeping you well and healthy

it's now actually attacking healthy tissue within your body

by mistake. And what that means is that healthy tissue can become damaged and the sight of that healthy

tissue will determine very much what the disease is.

We tend to think of the immune system as a sort of body-wide defense.

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