Exactlywhy someone develops multiple sclerosis (MS) isn't known. It's not caused by anything you've done and it's not clear whether it can be prevented.
What is known so far suggests it's caused by a combination of genetic and environmental factors.
MS is an autoimmune condition, which means your immune system mistakes part of your body for a foreign substance and attacks it.
In the case of MS, it attacks the myelin sheath in the brain and/or spinal cord. This is the layer that surrounds your nerves, protecting them and helping electrical signals travel from the brain to the rest of the body.
The attacks cause the myelin sheath to become inflamed in small patches (plaques or lesions), which can be seen on a magnetic resonance imaging (MRI) scan .
These patches of inflammation can disrupt the messages travelling along the nerves. It can slow them down, jumble them, send them the wrong way, or stop them from getting through completely. This disruption leads to the symptoms and signs of MS.
When the inflammation goes away, it can leave behind scarring of the myelin sheath (sclerosis). These attacks, particularly if frequent and repeated, can eventually lead to permanent damage to the underlying nerves.
It's notclear what causes the immune system to attack the myelin sheath.
It seems likely that it's partly caused by genes you inherit from your parents and partly by outside factors that may trigger the condition.
Some of the factors that have been suggested as possible causes of MS include:
More research is needed to further understandwhy MS occurs and whether anything can be done to prevent it.
Multiple sclerosis (MS) is a condition which can affect the brain and/or spinal cord, causing a wide range of potential symptoms, including problems with vision, arm or leg movement, sensation or balance.
Read about the main symptoms of multiple sclerosis (MS), including fatigue, unusual sensations, difficulties with movement and vision problems.
Exactly why someone develops multiple sclerosis (MS) isn't known. It's not caused by anything you've done and it's not clear whether it can be prevented.
It can be hard to tell whether your symptoms might be caused by multiple sclerosis (MS) at first, as some of the symptoms can be quite vague or similar to other conditions.
There's currently no cure for multiple sclerosis (MS), but it's possible to treat the symptoms with medications and other treatments.
You may have to adapt your daily life if you're diagnosed with multiple sclerosis (MS), but with the right care and support many people can lead long, active and healthy lives.
Jo was diagnosed with multiple sclerosis after the birth of her son. She explains how it affects her body, her ability to move around and her family life.
Narinder Kaur-Logue has an aggressive form of relapsing remitting multiple sclerosis. She experiences debilitating fatigue on a daily basis and has regular relapses.
Leonie Martin, age 45, has relapsing-remitting multiple sclerosis.She explains how she learnt to manage her symptoms.