There are estimated to be around 100,000 people with MS in the UK and perhaps as many 2,500,000 worldwide. Those effected are generally in North America, North and West Europe and Australasia. Most who tend to be affected are women with an approx 3 to 2 ratio.
What it is?
It's a condition which effects the Central Nervous System (CNS). This consists of your brain and spinal cord. The nerves travel from the brain, into the spinal cord and around your body. Your brain controls all bodily activities, such as thought and movement. In short it is these nerves that are damaged and as a result it interfers with the body.
Source: MS Society
The nerves described above are protected by a substance called myelin, this makes sure that the messages sent around the body travel quickly and smoothly. An easier way to describe this is to think about an electrical cable and the outer covering protects the inner wires.