Everyone has those days when you feel overworked and overtired. Perhaps you woke up before your alarm and couldn’t fall back asleep, or maybe you went to bed late after a night out with friends.

Though cases of occasional fatigue normally have an identifiable cause, chronic fatigue is a near-constant state of weariness that doesn’t seem to go away no matter how much rest you get.

According to the Centers for Disease Control and Prevention, about 1 in 3 Americans reports that they do not get enough sleep.

Sleep deprivation can cause daytime sleepiness and may affect your ability to concentrate in the short-term, but the fatigue that lasts for days on end can actually have a negative impact on your health, both mental and physical.

In this article, we’ll explore the topic of fatigue in greater depth to determine exactly what it is and what causes it.

We’ll also review the symptoms of fatigue and discuss how it can be diagnosed and treated.

What is Fatigue?

What is Fatigue

After getting a good night’s rest, most people wake up feeling refreshed and ready to conquer the day.

For others, however, the morning always seems to come too soon, and you don’t feel rested no matter how long you slept.

Each day becomes more difficult to face when you spend the entire day feeling weary, tired, and out of sorts.

Fatigue is not a disease or a sleep condition, but it is a symptom of many sleep disorders.

It is a lingering feeling of tiredness that is constant or near-constant and may have a negative impact on your ability to fulfill daily tasks.

With fatigue, you may experience persistent, unexplained, and recurrent episodes of exhaustion – it is similar to the exhaustion you feel when you have missed a lot of sleep or when you are sick with the flu and simply can’t seem to muster the energy to get through the day.

The difference between being tired and fatigue is that fatigue is not relieved by rest.

It is a state of constant weariness that develops over time and drains your motivation, your energy, and your concentration. Chronic and severe fatigue can affect your performance at work, in school, and even in your home life.

It can also have an impact on your emotional and psychological well-being.

What Are the Symptoms of Fatigue?

Symptoms of Fatigue

The National Heart, Lung, and Blood Institute (NHLBI) recommends 7 to 8 hours of sleep per night for adults over the age of 18.

If you don’t get enough sleep for even one night, you could experience the effects of sleep deprivation.

What many people do not realize is that fatigue can happen even when you’ve gotten the recommended amount of sleep. Here are some of the symptoms of fatigue:

  • A chronic feeling of tiredness or sleepiness
  • Headaches or migraines
  • Dizziness or lightheadedness
  • Sore or aching muscles
  • Slowed reflexes
  • Muscle weakness
  • Impaired judgment and decision-making
  • Changing moods, such as irritability
  • Loss of appetite
  • Impaired immune system function
  • Short-term memory problems
  • Poor concentration and focus
  • Hallucinations or psychosis
  • Difficulty paying attention to the task at hand
  • Low level of motivation

Fatigue manifests in different ways in different people, often dependent on the underlying cause for the fatigue. To better understand the different causes of fatigue and their impact, let’s talk about the three different types of fatigue:

  1. Physical Fatigue
  2. Mental Fatigue
  3. Metabolic Fatigue

Now, let’s take a closer look at each of these three types of fatigue in greater detail.

  1. Physical Fatigue

This is the kind of fatigue in which your body feels too heavy to move.

Your muscles feel weak, your movements slow, and you feel as if you’re moving in slow motion.

With this type of fatigue, you may feel physically incapable of performing daily tasks.

You might experience this type of fatigue if you pushed your body to its physical limits by working too hard, for too long, or at an unsustainable pace.

You do not have an endless supply of energy, and if you don’t get restful sleep to recharge, you’ll end up feeling fatigued and tired, both physically and mentally.

  1. Mental Fatigue

With this type of fatigue, you may find it difficult to stay awake or to stay focused on the task at hand.

This type of fatigue can have an emotional aspect to it as well.

For example, if you’ve been under a great deal of mental or emotional stress for an extended period of time, you may feel as if you are emotionally drained – this can then lead to a feeling of physical fatigue.

Mental fatigue can also be linked to mental health issues like depression, anxiety, and seasonal affective disorder.

  1. Metabolic Fatigue

This type of fatigue is linked to a number of medical conditions which can drain your body of energy and/or make it difficult to produce more.

Adrenal fatigue falls into this category. Adrenal fatigue happens when the adrenal glands produce too much stress hormone in response to some kind of stressor (either real or perceived).

If they continue to produce that hormone unnecessarily, it can lead to symptoms such as inexplicable tiredness, brain fog, trouble getting out of bed, poor memory, insomnia, and lack of energy.

Other conditions that can contribute to fatigue are discussed in the next section.

Not only are there different types of fatigue, but there are a wide variety of potential underlying causes. Keep reading to learn more about the medical conditions and lifestyle factors that can cause fatigue.

What Causes Fatigue?

What Causes Fatigue

Everyone experiences fatigue in their own way, and there may be more than one underlying cause for it.

In most cases, however, fatigue can be traced back to a particular habit or set of habits. It can also be related to an underlying medical or mental health condition.

The main categories into which the causes of fatigue can be divided are:

  1. Lifestyle Factors
  2. Medical Conditions
  3. Mental Health Conditions
  4. Sleep Disorders
  5. Chemicals or Substances

Now, let’s take a closer look at each of these causes for fatigue.

  1. Lifestyle Factors

You may not realize it, but your daily habits could be contributing to your fatigue.

For example, if you don’t get any exercise on a regular basis, your level of physical fitness could be very low and even simple daily tasks may cause you to feel excessively tired.

Using or abusing drugs, alcohol, and caffeine are lifestyle choices that can contribute to fatigue, as can lack of sleep, following an unhealthy diet, and engaging in other unhealthy activities.

  1. Medical Conditions

Fatigue is a symptom that many medical conditions share, and, in some cases, it may be that more than one medical problem is an underlying factor for chronic fatigue.

Here is a list of some of the medical conditions that can cause fatigue:

  • Addison’s disease
  • Anemia
  • Arthritis
  • Cancer
  • Chronic fatigue syndrome
  • Congestive heart failure
  • Diabetes
  • Eating disorders
  • Emphysema
  • Fibromyalgia
  • Hypothyroidism
  • Hyperthyroidism
  • Kidney disease
  • Liver disease

Several of the medical conditions on this list are linked to hormones.

Addison’s disease, for example, affects the adrenal glands, limiting their ability to produce enough of certain hormones.

Hypothyroidism is characterized by an underactive thyroid gland and reduced levels of thyroid hormone while hyperthyroidism is the opposite.

Cardiovascular and blood issues like anemia and congestive heart failure can contribute to physical exhaustion and fatigue, as can metabolic disorders like diabetes.

  1. Mental Health Conditions

Chronic fatigue is a common symptom among mental health conditions like anxiety, depression, and seasonal affective disorder.

Depression is caused by chemical imbalances in the brain which lead to problems with sleep and energy levels.

Anxiety and stress are closely linked and can contribute to fatigue as well.

When you are constantly worrying or feeling stressed, it can drain your energy and may make it more difficult for you to fall asleep at night which can lead to fatigue during the day.

  1. Sleep Disorders

When it comes to sleep disorders, it is important to differentiate between sleepiness and fatigue.

Sleepiness is a common symptom of sleep disorders such as narcolepsy, obstructive sleep apnea, and insufficient sleep syndrome – it commonly occurs when the sleep disorder prevents regular or adequate sleep at night.

Fatigue, on the other hand, often occurs even when the patient gets adequate sleep. So, while sleep disorders and fatigue may be concurrent, the sleep disorder is not always the primary cause.

  1. Chemicals or Substances

Everything you put into your body has the potential to affect your health, and certain substances are known for inhibiting sleep which can contribute to fatigue.

For example, certain antidepressants, antihistamines, anti-anxiety drugs, and even sedatives can cause you to feel fatigued – they may also make it more difficult for you to sleep at night which might make matters worse.

Vitamin and mineral deficiencies, overuse of alcohol or caffeine, and even certain supplements can also cause fatigue.

In addition to these five categories, some of the other potential causes for fatigue include chronic pain that makes it difficult to sleep, being overweight or underweight, and lack of physical exercise.

How is Fatigue Diagnosed?

How is Fatigue Diagnosed

Diagnosing the underlying cause of your fatigue can be difficult since there is such a wide variety of symptoms.

If you are concerned about the frequency or severity of your daytime exhaustion, talk to your doctor.

To help diagnose your problem, he will perform a physical exam to rule out underlying medical problems and may also ask questions about your symptoms.

Before you visit your doctor, it might help to think about your symptoms and to write down details relating to any patterns you notice as well as your sleep habits, because the two may be linked.

In addition to performing a physical exam and medical history, your doctor may also use certain diagnostic tests to identify the underlying cause.

Urine tests, blood tests, imaging scans, and mental health questionnaires can all be useful diagnostic tools. Once your doctor identifies the underlying problem, the two of you can work together to determine a course of treatment.

What Are the Treatment Options for Fatigue?

In most cases, treating the underlying cause for your fatigue will be effective in resolving your symptoms.

For example, if your fatigue is related to anemia then increasing your iron intake could reverse both the condition itself and your fatigue.

Sleep apnea can be treated with continuous positive airway pressure (CPAP) therapy, hypothyroidism with synthetic thyroid hormone supplements, and mental health issues with medication and/or therapy.

Because there are so many potential underlying causes for fatigue, the treatment options are nearly endless.

Your doctor will first need to make and confirm an accurate diagnosis to identify the condition and then start working on a treatment plan.

If you have more than one medical or mental health problem, treatment could be a little trickier, so you’ll need to work closely with your doctor to find a treatment plan that really works for you.

In addition to treating any underlying medical or mental health issues contributing to your fatigue, there are certain lifestyle factors you can change to reduce your symptoms.

Here are some simple things you can do in your daily life to reduce fatigue:

  • Stay hydrated by drinking plenty of fluids
  • Do your best to follow a healthy and balanced diet
  • Get regular exercise, at least 30 minutes five times a week
  • Aim to get 7 to 8 hours of sleep every night
  • Avoid things you know will stress you out
  • Don’t take on more work than you can reasonably handle
  • Make time for relaxing activities like yoga or meditation
  • Limit your consumption of alcohol and tobacco

The kind of fatigue that leaves you feeling mentally and physically drained on a daily basis takes time to develop, so you should not expect to cure it overnight.

Correcting an underlying medical problem may have near-immediate results, but you should be prepared to take some time in treating your fatigue.

With the help of your doctor and a personalized treatment plan, however, you can find relief.

Disclaimer: The information on this website is not intended to be used as a substitute for professional medical advice, clinical diagnosis, or treatment. Always seek the advice of your personal physician or another qualified health provider with any questions you may have regarding a medical condition.


About Kelsey Woodbridge Kelsey is a lover of anything comfy, especially her bed. In fact, you will most likely find her in her bed drafting a new article, watching New Girl, or just lounging in fuzzy socks.