The Bone Crushing Fatigue That Comes with Multiple Sclerosis

Up to 75% of people suffering from multiple sclerosis get mental fatigue. Many of these people say that the mental exhaustion is actually the worst part of having this disease.

Why does a physically debilitating disease come with mental exhaustion, too?

What causes this mental fatigue?

When we think of multiple sclerosis, we tend to think about losing our strength and physical abilities much more than our cognitive ones. But cognition is such a huge part of life, and it seems like mental exhaustion can be even more bothersome than some physical disabilities. Sometimes you might get so tired you can't even get your sentences out right. It's depressing when you can't even enjoy reading your favorite book because you're so tired. These are all things that many people take for granted because normally, you would have the energy to do them.

The mental exhaustion seems like it comes from nowhere

But it's not that you're tired physically either. You didn't just run a marathon or finish a bunch of chores. No, maybe you just woke up from a long night of sleep, but you're still tired. Why is that? Why do people suffering from multiple sclerosis, a condition that affects your nervous system, make you so mentally exhausted?

Unfortunately, mental fatigue is just as elusive to researchers as it is to us. It's difficult to pin down and study because of how vague it is and how different it can be for different people. It's kind of like tracing a cloud, or holding water in your hands - it's simply very difficult to grasp mental fatigue in a discrete way. But mental fatigue is extremely disabling, and so it's still important for researchers to try and find some answers.

How do you compare how tired you feel to how others feel?

One of the hardest things for researchers to do is actually measure the amount of fatigue someone is having. It's all relative, and what one person says is a 10 out of 10 might be someone else's 4 out of 10. Because everyone's opinion is different, it's difficult for researchers to quantify how much fatigue someone is actually experiencing. People have been trying to study fatigue for over a century, and no one's figured out yet the best way to measure it.

Physical fatigue is much easier to study because it's simpler to measure

Mental fatigue is different from physical fatigue. Physical fatigue is easier to measure because it will actually affect how well you can complete a measurable task. For example, doing push-ups over and over will eventually tire you out. Someone who tires out easier is going to be able to do fewer push-ups in a row. This clear way to measure the level of fatigue a person is experiencing gives researchers something to measure. However, take math problems as an example for a test of mental fatigue. With math, eventually you get tired, but you can still do the problems. How can researchers measure your fatigue if you're still capable of the said task?

Read on to learn more about measuring fatigue.