Mental fatigue can be a vicious cycle, causing a loss of productivity and trouble sleeping. (Photo by Vitaly Gariev)

Everyone feels tired at some point. The signs of physical fatigue are often easily recognizable. Slower movements, heavy eyes, achy muscles, and even frequent yawning are some telltales signs that a body is tired. But what about mental fatigue?

Mental fatigue affects the mind instead of the muscles. That can make mental fatigue difficult to spot. But identifying the presence of mental fatigue is important, as untreated mental fatigue can affect decision-making and performance at work and in the classroom. Anyone can develop mental fatigue, but those who find themselves frequently overwhelmed by work, school or personal obligations may be particularly vulnerable.

Recognition of the following signs of mental fatigue may compel those dealing with such exhaustion to take a break and seek help:

· Mood changes: People suffering from mental fatigue may experience mood changes that would otherwise be considered out of character. Increased irritability, a shortened temper, a lack of patience for others, and increased instances of snapping at people are some mood changes that indicate the presence of mental fatigue.

· Loss of productivity: A noticeable dip in productivity is another sign of mental fatigue. Loss of productivity induced by mental fatigue occurs because the feeling of tiredness compromises a person’s ability to concentrate. Mental fatigue also can drain a person’s motivation. Distractions become harder to ignore when suffering from mental fatigue, which in turn diminishes productivity.

· Instances of zoning out: Mental fatigue can get in the way of a person’s ability to focus on what he or she is doing. This sense of zoning out can be particularly dangerous, as it can strike even when driving a vehicle. Links have been made between mental fatigue and car accidents.

· Inability to sleep: It may seem counterintuitive that mental fatigue would make it difficult to sleep, but it can. People with mental fatigue may struggle to wind down and stop thinking about work- or school-related tasks come bedtime. That can trigger insomnia. One of the dangers associated with this side effect of mental fatigue is that lack of sleep can worsen feelings of exhaustion.

· Increased anxiety: Mental fatigue can trigger the sympathetic nervous system, which can lead to feelings of anxiety and panic. These feelings may be ever-present.

· Physical side effects: Some people find it harder to exercise when their minds are fatigued. A 2017 study published in the journal Sports Medicine found that the duration and intensity of a physical task are important variables when considering the potential effects of mental fatigue on physical performance. Researchers identified a decreased time to physical exhaustion, and a resulting decline in endurance performance, as a side effect of mental fatigue.

Mental fatigue can take a serious toll. Anyone who suspects they are suffering from mental fatigue is urged to contact a health care provider.