Cognitive fatigue is the deterioration in the ability to think effectively and maintain focus. Just like physical fatigue, prolonged mental activity can cause tiredness that affects the mind.

Various factors, such as stress and lack of sleep, can cause cognitive fatigue. Symptoms may include forgetfulness, making mistakes more frequently, and having difficulty concentrating.

People can manage cognitive fatigue by taking short breaks during challenging tasks. Preventive measures may include exercising regularly and getting enough sleep.

Read on to learn more about cognitive fatigue, including symptoms, causes, management, prevention, and what questions to ask a doctor.

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Cognition is the medical term for thinking. It can involve an array of mental processes, such as:

  • problem-solving
  • remembering
  • learning

According to research, cognitive fatigue denotes a decline in cognitive performance when engaging in tasks that require sustained mental activity. It may also refer to a subjective feeling of tiredness that occurs during such tasks.

According to licensed psychologist David Tzall, Psy.D, the symptoms of cognitive fatigue may vary. Some indicators include the following:

  • difficulty concentrating and staying focused when performing tasks, making decisions, and following conversations
  • a longer time necessary to complete mental tasks that someone typically performs quickly
  • manifestation of forgetfulness and difficulty recalling information or events
  • reduced ability to solve complex problems or think critically
  • limited creativity
  • more frequent mistakes

Tzall notes that there are a variety of causes of mental fatigue. They may include:

  • Tiredness and lack of sleep: Sleep is essential for cognitive functioning, and sleep deprivation can reduce:
    • attention
    • memory
    • decision-making
  • Stress: High levels of stress can negatively affect cognitive performance, leading to decreased:
    • focus
    • attention
    • memory
  • Mental workload: When the brain is overloaded with information or tasks, it can become challenging to process everything effectively.
  • Age-related cognitive decline: Certain cognitive functions may naturally decline as people age, leading to more frequent cognitive lapses.
  • Medical conditions: Certain medical conditions — such as Alzheimer’s disease, dementia, or brain injuries — can negatively affect cognitive function.
  • Multitasking: Trying to juggle multiple tasks simultaneously can divide attention and result in suboptimal mental performance.
  • Mental health issues: Certain mental health conditions — such as depression and anxiety — can reduce cognitive function and lead to difficulties in concentration and memory.
  • Environmental factors: Low lighting, excessive noise, or other environmental factors can interfere with cognitive processing.
  • Inadequate nutrition: Poor diet and nutritional deficiencies can hinder optimal brain health.
  • Medications and substances: Some medications or substances — including alcohol and harmful drugs — can affect cognitive abilities and lead to lapses in judgment and memory.

Counselor Marty A. Cooper, PhD, LMHC, NCC describes a three-step process below that can help manage cognitive fatigue:


“When people notice they are feeling tired, the first thing they should do is stop whatever tasks they are doing,” says Cooper.

“Individuals may feel reluctant to take a 5- or 10-minute break because they think it may put them behind schedule. However, addressing the cognitive fatigue and returning to work refreshed will help promote more effective and efficient work.”


“During the break, it is time for a person to check their mind and body,” says Cooper. “This involves asking themselves where they are carrying tension, such as the temples or back.”

A person can try to check in with what their mind is doing. Is it jumping from one thought to another? Try to get in touch with what one is feeling or thinking.


“Based on what people learn from their checking in, they can make some quick adjustments to get a break from the fatigue,” says Cooper. “This may involve getting a few minutes’ reprieve from stimuli and activity.”

Some examples include:

  • turning off the computer or other electronic device
  • dimming the lights
  • removing external sounds, such as the TV
  • slowing down

Cooper offers the following tips to help prevent or minimize cognitive fatigue:

  • Sleep: Cognitive fatigue can set in when people are not sleeping enough. If attaining quality sleep is challenging, it is beneficial to see a professional for guidance.
  • Schedule: Overscheduling or having too many competing demands can also lead to cognitive fatigue. It is important to schedule breaks to allow the mind and body a chance to reset throughout the day.
  • Regular exercise, including mindfulness: Regular exercise releases all of the feel-good chemicals in the brain that can help prevent fatigue. Also, adding mindfulness activities — such as meditation — can foster relaxation and help refocus attention in the present moment.

A person who feels they are experiencing cognitive fatigue may consider asking a doctor the following:

  • Are my symptoms of cognitive fatigue significant?
  • What may be the cause in my case?
  • Could you make some individualized recommendations for me that may help?

Cognitive fatigue is a decline in task performance that entails sustained mental activity. It may manifest in making frequent mistakes, difficulty staying focused, and taking longer to complete tasks.

Management can include taking short breaks and getting a brief reprieve from stimuli, such as noise and light.

If a person’s symptoms of cognitive fatigue are troubling, they may wish to discuss them with a doctor.