Fatigue is one of the most common, troubling symptoms experienced by people with MS. For some people, it is the symptom that affects them most.
Last updated: 3rd March 2021
MS fatigue is not only difficult to define but it is an invisible symptom (in other words, others can’t see it). This can make it difficult to understand or explain to others who may interpret it in the wrong way. It is often described as heavy tiredness (lassitude), general weakness or lack of energy but for some it may be described as total exhaustion.
The reality is that every definition is correct because the experience is subjective and everyone experiences MS fatigue differently.
To find out more about MS fatigue, download the guide Fatigue: an invisible symptom of MS and keep reading below. This guide is packed full of tips for managing MS fatigue, including exercises you can do at home and a fatigue diary.
What causes MS fatigue?
The causes of MS fatigue are not yet well understood. It is thought to result from a range of different factors, partly caused by MS itself (known as primary fatigue) and partly by other factors (secondary fatigue).
Primary MS fatigue is due to changes in the brain and damage to the central nervous system. The damage affects the nerves by interrupting messages from the brain and spinal cord to the rest of the body. As a result, your body has to work harder to function, which can lead to a build-up of MS fatigue. Muscle weakness and cognitive demands are also affected by the changes in the brain, so they too use more energy, which can lead to MS fatigue.
Secondary MS fatigue occurs from the effects of living with MS. For instance, MS symptoms such as depression, pain or sleep disturbance from spasms or incontinence can all make MS fatigue worse. MS fatigue may also occur as a side effect of some medications or from inactivity, stress, poor diet or an infection. Other medical conditions can also cause or worsen MS fatigue.
How is MS fatigue different to ordinary fatigue?
MS fatigue is more than the tiredness that everybody feels after exertion or missing a good night’s sleep. This type of tiredness can still affect you, but MS fatigue goes beyond that.
MS fatigue can be physical and mental; it saps energy in an instant and can stop you from completing tasks. MS fatigue can be very debilitating and, unlike ‘ordinary’ fatigue, it can take a long time to recover from.
MS fatigue is often overwhelming. It can happen at any time without warning or without any apparent reason. Some people say they experience MS fatigue after gentle activities such as writing or reading and they immediately need to rest.
Others say that MS fatigue happens after physical exertion, such as taking the dog for a walk or doing the shopping. For others, MS fatigue can happen after cognitive exertion such as working on the computer and completing mentally-demanding tasks. You may also experience MS fatigue when you wake up, in some cases every day, even after a good night’s sleep.
How to describe MS fatigue to others
It can be complicated to describe your MS fatigue to friends, family, colleagues and healthcare professionals, but helping others to understand can make your daily life with MS fatigue less frustrating.
Sometimes friends and family may notice the effects of MS fatigue. For example, a relative might notice that you are walking more slowly later in the day, or they may notice that after completing certain tasks you become much slower in responding to conversations. Seeing the effects of MS fatigue can help those around you to offer assistance and support.
There will be times when your MS fatigue is not obvious to others, because it is an ‘invisible’ symptom. Using analogies or metaphors to describe MS fatigue can help friends, family and colleagues understand and relate to what you are experiencing.