What is multiple sclerosis?

Multiple sclerosis is an autoimmune disease. This means that the immune system attacks the body's own tissues, instead of fighting off foreign bodies such as pathogenic bacteria.

In multiple sclerosis, the immune system attacks myelin, the main component of the protective sheath that surrounds nerve fibres in the central nervous system.

Myelin is partially or completely stripped from the nerve fibres disrupting nerve transmission between the brain and the rest of the body via the central nervous system.

This produces physical problems such as difficulties in moving, and can cause emotional and mental problems as cognitive processes slow down.

The exact origin of the disease and a cure has yet to be found, but treatments are available that help relieve symptoms and may slow progression.

What causes multiple sclerosis?

Almost 150 years since multiple sclerosis was first recognised, we know that MS is an auto-immune disorder but we still do not know exactly what triggers this, and why it affects some people and not others.

There are several theories and most experts agree that MS is probably due to a combination of genetic and environmental factors.

Types of multiple sclerosis

There are 4 main types: 

Relapsing remitting multiple sclerosis (RRMS)

Symptoms appear sporadically during a relapse, followed by full or partial recovery during a period of remission. 

Secondary progressive multiple sclerosis (SPMS)

Symptoms progressively increase, but this might be very slow and barely noticeable.

Primary progressive multiple sclerosis (PPMS)

Symptoms gradually get worse from the start, rather than appearing as relapses.

Benign multiple sclerosis (BMS)

Only very occasional relapses, with good recovery in-between, and minimal symptoms over 10 to 20 years.