The increases in Auto Immune Diseases is one sign that he earths electromagnetic field ( EM Field ) is weakening (1).
Auto Immune Diseases have risen 400% (2) or more ( some claim in the thousands ) for the last 2 decades which coincides with a decrease in the electromagnetic fields strength.
The EM Field protects the earth from harmful solar radiation carried on the solar winds.
Everyday the earth is bombarded with this solar energy and the EM Field stops a large amount of that energy from reaching us.
In general, we are not told that the EM Field is weakening, and we are absolutely not told that, that weakening may be causing an increase in disease.
How does this relate to Auto Immune Disease? Lets examine one of those. Multiple Sclerosis (MS).

Multiple sclerosis is a disease that affects the brain and spinal cord resulting in loss of muscle control, vision, balance, and sensation (such as numbness). With MS, the nerves of the brain and spinal cord are damaged by one’s own immune system. Thus, the condition is called an autoimmune disease.(3)

From: USMS: If you take a look at the map, you’ll notice that a significantly higher incidence of MS  is found in the northernmost latitudes of the northern and the southern hemispheres compared to southernmost latitudes.
It seems that the further you are away from the poles, the less likely you are to have MS. Why is this?
If you look at the EM Field you can see that it is strongest at the equatorial line. At the poles it is weakest, which is why we have the
Northern and Southern Lights.

In the far northern and southern  skies we often have a view of a beautiful phenomenon known as the northern lights or southern depending on location.
The temperature above the surface of the sun is millions of degrees Celsius. At this temperature, collisions between gas molecules are frequent and explosive. Free electrons and protons are thrown from the sun’s atmosphere by the rotation of the sun and escape through holes in the magnetic field. Blown towards the earth by the solar wind, the charged particles are largely deflected by the earth’s magnetic field. However, the earth’s magnetic field is weaker at either pole and therefore some particles enter the earth’s atmosphere and collide with gas particles. These collisions emit light that we perceive as the dancing lights of the north (and the south).

This gives credibility to a close friends theory that at least in part, some of the cause for this increase in diseases of the immune system is due to the weakening of the EM Field.
Example: This friend was diagnosed in 2006 with MS. His neurologist suggested that he had had this disease for a decade or more due to the amount of damage his brain had already taken during the course of the diseases progression. He had a severe exacerbation ( disease flare up ) in late October / early November of that year, which led him to seek help. Oddly enough, that was a time period where we had very high solar activity.
Coincidence? Seems Unlikely given the facts above.

An ever-increasing number of studies has clearly shown various biological and medical effects at the cellular level due to electromagnetic fields, including power–frequency, radiofrequency and microwaves. Such fields are present in everyday life, at the workplace, in homes and places of leisure. ( Not to mention those surrounding us from solar flares )

For the most part, no correlation has been related to the EM Field and Auto Immune Disease. I for one, after researching this find it to be highly suspect.
We are kept in the dark for so many reasons about so many things. We can do nothing about the EM Field; is that why this topic is left in the dark?
Is there enough evidence to at least warrant a study to see if this theory is sound? I believe there is.

Are the bodies of government and the medical community keeping that data to themselves?
Either the theory isn’t sound or those in power don’t want you to know.
We’ll let you judge that for yourself.

References:
http://en.wikipedia.org/wiki/Earth%27s_magnetic_field
(1) http://news.nationalgeographic.com/news/2004/09/0909_040909_earthmagfield.html
(2) https://aarda.org/press_release_display.php?ID=47
(3) http://www.webmd.com/multiple-sclerosis/guide/what-is-multiple-sclerosis
http://www.unitedspinal.org/msscene/2009/10/06/mapping-multiple-sclerosis/
http://www.northernlightscentre.ca/northernlights.html
http://www.scribd.com/doc/14987547/Disturbance-of-the-immune-system-by-electromagnetic-fields