What is MND?

With motor neurone disease, known as MND, messages from the motor neurones gradually stop reaching the muscles. This leads the muscles to weaken, stiffen and waste, which can affect how you walk, talk, eat, drink and breathe. Some people also get changes to their thinking and behaviour, but the disease affects everyone differently. Not all symptoms will affect everyone, or in the same order. Symptoms also progress at varying speeds, which makes the course of the disease difficult to predict.

MND is life-shortening and there is no cure. Although the disease will progress, symptoms can be managed to help achieve the best possible quality of life.

We provide an overview about MND in our Introduction to motor neurone disease booklet, which is also available as an audio version. More detail can be found on our information for people with or affected by MND page.

How many people are affected?

MND affects up to 5,000 adults in the UK at any one time. There is a 1 in 300 risk of getting MND across a lifetime. It can affect adults of any age, but is more likely to affect people over 50.

We provide further statistics if you would like more detail, but please be aware these contain sensitive content.

As motor neurone disease is not common, general health and social care professionals may not see many cases. This means it is important to seek out specialists who have appropriate experience in its treatment and care – usually with referral to neurological services. For more information, see our pages about health and social care services for MND.

Motor neurone disease (MND) causes a range of symptoms, which progress at varying speeds. These can appear in a different order for each individual, but you may be diagnosed with a particular type, due to the way your symptoms appear. The four main types are described below. Each type does not describe a completely separate disease, just a different form. In other words, each type is a way of describing how the disease is likely to affect you.

Each type can be difficult to diagnose, as they have overlapping symptoms. Over time, symptoms and the rate at which they progress become clearer. This means your diagnosis may be reviewed and changed to another type.

Amyotrophic lateral sclerosis (ALS): 

This is the most common form of MND, with weakness and wasting in the limbs, muscle stiffness and cramps. Someone may notice they are tripping when walking or dropping things. Life expectancy is usually two to five years from the onset of symptoms.

Bulbar onset MND or Progressive bulbar palsy (PBP): 

PBP affects a smaller number of people than typical ALS, and mainly affects the muscles of the face, throat and tongue. Early symptoms may include slurring of speech or difficulty swallowing. Life expectancy is between six months and three years from onset of symptoms.

Progressive muscular atrophy (PMA): 

PMA affects only a small proportion of people. Early symptoms may show as weakness or clumsiness of the hands. Life expectancy is usually more than five years. See information sheet 2D – Progressive muscular atrophy. Contact our MND Connect helpline for details about an email group for people with PMA or PLS (the MND Association is not responsible for the group or moderation of its content).

Primary lateral sclerosis (PLS): 

PLS is a rare form of MND, causing mainly weakness and stiffness that usually begins in the lower limbs, although many people experience additional problems with their speech and various other symptoms. For detailed information about PLS, its full range of symptoms and management, see our information sheet 2C – Primary lateral sclerosis. PLS is usually not life-shortening, as it progresses very slowly. It may take some time to confirm a definite diagnosis of PLS because slow progression in ALS may look similar at first. Contact our MND Connect helpline for details about an email group for people with PMA or PLS (the MND Association is not responsible for the group or moderation of its content).

Kennedy’s disease (also known as spinal bulbar muscular atrophy or SBMA): 

While not a type of MND, Kennedy's disease has similar symptoms. It is a rare condition affecting the motor neurones, with increasing weakness and wasting of the muscles. Unlike MND, Kennedy’s disease also causes hormonal changes. Due to their similarities, MND and Kennedy’s disease are sometimes confused at diagnosis. Most people with Kennedy’s disease live an average life span. See our Kennedy’s disease pages and Information sheet 2B – Kennedy’s disease

Motor neurone disease (MND) affects everyone differently. Not everyone has all the symptoms, or in the same order, and the speed at which symptoms progress can vary. Seek help from your health and social care professionals at the first sign of any change.

MND cannot be stopped or reversed, but therapies, equipment and medication can help manage symptoms. These can all help you achieve the best possible quality of life. We cover symptom control in our range of information resources including our guide, Living with motor neurone disease.

You may have some or all of the symptoms listed below:

• muscle weakness, with loss of muscle mass (wasting), and both movement and mobility problems
• muscle cramps and spasms, including rippling sensations, known as fasciculation
• stiff joints, which limit range of movement
• pain or discomfort, as a result of other symptoms (pain is not usually caused by MND directly)
• speech and communication problems, affecting how you speak, gesture and show expression
• swallowing difficulties, affecting how you eat and drink
• saliva problems, where thin saliva pools in the mouth or saliva becomes thick and sticky
• weakened coughing, which makes it harder to clear the throat
• breathing problems, which can lead to breathlessness and fatigue
• emotional lability, with inappropriate emotional responses, such as laughing when feeling sad
• changes to thinking and behaviour, for about half of those diagnosed with MND and this number increases in the later stages.

Changes to thinking and behaviour are usually mild, but a small number of people with MND may develop frontotemporal dementia, which is more severe and needs additional care support. See our booklet on Changes to thinking and behaviour with MND.

The senses are usually unaffected, so people can still see, hear, taste, smell and feel sensations. Some people may experience changes to taste, skin hypersensitivity or problems with temperature regulation.

Bladder and bowels are not usually affected by MND, but it may be harder to get to the toilet in time if mobility is affected. Constipation can also be a problem if you become less mobile or get dehydrated. Ask your GP for guidance.

Sexual function is not affected, but sexual expression may become more difficult if mobility and movement are restricted. See our booklet on Sex and relationships.

There are several forms of motor neurone disease, known as MND and amyotrophic lateral sclerosis (ALS) is the most common form or type of the disease.

In the UK we use motor neurone disease (MND) as an umbrella term to cover all forms of the disease. In the USA, they use ALS as the umbrella term.

You can find out more in Are there different types of MND?  above.