What is MS?

Multiple sclerosis (MS) is one of the most common diseases affecting the central nervous system. It’s a chronic condition, affecting nerves in the brain and spinal cord. These nerves usually send signals to the rest of the body in the form of electrical impulses to coordinate activities including movement, cognition and sensation. To ensure the messages are transmitted quickly and efficiently, the nerves are sheathed in a fatty insulating material called myelin.  

In MS, your immune system attacks these myelin sheaths, causing inflammation and damage and resulting in the formation of scar tissue (known as lesions or plaques). These effects on the myelin sheaths can disrupt the ability of the nerves to conduct electrical impulses, and it is this which can then result in a range of different symptoms that are characteristic of MS. The term multiple sclerosis means 'many scars'.

It is not known what causes MS; however, a virus, gene defect or environmental factors may play a role.  

What are the symptoms of MS?

Everyone’s experience of MS is different, so the way it appears can differ between individuals, and, from time to time, even within the same person. MS symptoms are unpredictable and may vary with each attack. They also vary from person to person, depending on the part of the nervous system that is affected.

There is a range of potential symptoms, which can be divided into different groups, including:  

  • Physical symptoms – caused when lesions affect nerves that relate to physical functions, such as visual problems (which can include blurring of vision or double vision and occasionally loss of sight), loss of balance and co-ordination (ataxia), fatigue or muscle stiffness and spasms.
  • Sensory symptoms – such as numbness and tingling.
  • Cognitive symptoms - symptoms affecting the way you think, such as problems with memory, concentration, and judgment, or emotional changes.
  • Sexual symptoms – impotence, diminished arousal, loss of sensation.

Most people only experience a few of these symptoms – it is unlikely that someone would develop all of them. Symptoms also change over time, so a symptom might only appear once, while others might stay over time and might also get worse.

The symptoms also affect people differently: in some people, they develop steadily over time; in others, they come and go. Periods when symptoms get worse or when new symptoms appear are known as relapses; when symptoms improve or disappear, it is called a remission.  

There are different types of MS…

Around 85% of people with MS are first diagnosed with a relapsing form of MS also known as ‘relapsing-remitting MS’ (RRMS) where symptoms appear and then go away, either partially or completely (remission). Relapses can last anything from days to months. 

Around half of all people with RRMS will develop secondary progressive MS (SPMS). In these cases, there is development of progressive disability with or without relapses and no definite periods of remission.

Less common at diagnosis is primary progressive MS (PPMS), which affects around 10% of people with multiple sclerosis. With PPMS, symptoms are progressive from the outset, and gradually get worse over time rather than coming and going as relapses.

Who does MS affect?

Worldwide estimates show MS affects around 2.1  – 2.5 million people, including around 100,000 people in the UK.  

MS affects twice as many women as men, though researchers are not sure why. It can develop at any age, however symptoms most commonly first appear between the ages of 20 and 40.

White people, particularly those whose families originated in northern Europe, are at the highest risk of developing MS.  However, even though it’s less common in non-white people, research has confirmed MS to be a truly global disease, affecting those from all continents. 

Living with MS

Living with MS can feel like a challenge, and you may experience feelings of frustration. However, there are therapies that may slow the disease.  The goal of treatment is to control symptoms and help you maintain a normal quality of life.

Although MS is recognised as a chronic condition, through improved medical and nursing care, people with MS can be expected to have a normal or near-normal life expectancy. 

Where to find out more 

MS Society: A site dedicated to helping improve the lives of people with multiple sclerosis in the UK.

MS Trust: Information & support for people with MS, their friends and families.

NHS: For general information on health.

MS Ireland: Information and support for people with MS in Ireland, their families and friends.