Causes of Fatigue: What’s Behind Your Tiredness

It’s normal to sometimes feel tired. However, persistent fatigue and a constant lack of energy can indicate an underlying medical condition.

Fatigue is a debilitating and disruptive symptom that can be linked to autoimmune diseases, sleep disorders, metabolic imbalances, poor dietary habits, or chronic stress.

Let’s talk about fatigue symptoms and the common causes of chronic fatigue.

What is fatigue?

Fatigue is a feeling of tiredness and exhaustion not relieved by rest or sleep. It’s a common symptom linked to various medical conditions, such as anemia, chronic fatigue syndrome, heart disease, depression, and sleep apnea.

Fatigue can also be triggered by lifestyle factors such as poor diet, lack of physical activity, insufficient sleep, and persistent stress.

Common symptoms associated with fatigue include:

Feeling constantly tired, even after getting enough sleep
Lack of energy or motivation
Trouble concentrating
Irritability or mood swings
Slow reactions and reflexes
Difficulty with memory and thinking

If you suspect an underlying medical condition may cause your fatigue, it’s important to consult a doctor.

A thorough physical examination, blood tests, and other medical evaluations can identify fatigue-related causes, including iron deficiency anemia, autoimmune disorders, or underactive thyroid function.

While some conditions linked to fatigue can be diagnosed quickly, other causes may be less obvious, making it challenging to discover what may contribute to persistent exhaustion.

Here are two common underlying health issues linked to unexplained fatigue.

1. Adrenal fatigue

Adrenal fatigue is a result of overworked or exhausted adrenal glands that can result in fatigue-related symptoms.

“During periods of stress, the adrenal glands release adrenaline and cortisol,” explains Dr. Berg. “These hormones help regulate the body’s stress response and play key roles in hormonal balance, metabolism, and blood sugar regulation.”

Prolonged or chronic stress may overwork the adrenal glands, potentially contributing to fatigue, blood sugar fluctuations, and reduced resilience to stress.

Other symptoms associated with adrenal fatigue include sleep problems, mood swings, anxiety, and salt cravings.

2. Chronic Fatigue Syndrome

Chronic Fatigue Syndrome (CFS) is a complex condition characterized by extreme and debilitating fatigue that doesn’t appear to be connected to any underlying medical condition.

Research published in the Journal of Translational Medicine indicates that the exact cause of CFS remains unclear. It’s believed to involve a combination of factors, such as disrupted sleep patterns, viral infections, nervous system irregularities, hormonal imbalances, and genetic predisposition.¹

Watch the video below to learn more about the causes of fatigue.

Common causes of fatigue

The human body is complex, and imbalances in one system can quickly impact overall physiological functioning, leading to fatigue and related symptoms.

While fatigue can be a symptom of one specific underlying imbalance, it can also result from a combination of factors, often making it challenging to diagnose its exact cause.

Let’s look at five common causes of fatigue.

1. Nutrient deficiencies

Poor dietary habits and lack of essential nutrients can disrupt energy metabolism, lead to hormonal imbalances, and impact sleep, both of which are risk factors for developing fatigue.

Here are common nutrients needed for optimal energy metabolism and restful sleep.

Vitamin B12 and folate

Vitamin B12 and folate play a vital role in the production of energy. Both nutrients are needed to produce red blood cells, which carry oxygen to all the cells in the body. When your cells are well-oxygenated, they can produce energy more efficiently.

Iron

Iron is a component of hemoglobin, a protein in red blood cells that binds to oxygen and carries it to all cells in the body, where it’s used to produce energy.

Vitamin B1

Vitamin B1 plays a crucial role in converting fuel into energy, and a deficiency can quickly lead to fatigue and low energy levels.

Diets high in refined carbohydrates and sugars can deplete vitamin B1 stores, which helps explain why poor nutrition often leaves you feeling tired and drained.

Magnesium and potassium

Magnesium and potassium are closely linked to energy-making processes and are needed for relaxation and rejuvenation.

Inadequate amounts of these minerals can increase the risk of poor sleep, causing fatigue and tiredness.

Watch the video below to discover why nutrient deficiencies can cause fatigue.

2. Stress

Stress can lead to fatigue by disrupting various physiological functions, depleting nutrient reserves, and interfering with energy production.

While cortisol is a critical component of the body’s stress response, prolonged levels of elevated cortisol can impact metabolic functions, dysregulated blood sugar levels, and trigger sleep issues, all of which can lead to fatigue.

Cortisol also profoundly impacts the brain, and research published in Advances in Integrative Medicine suggests that chronic stress can induce cognitive symptoms of fatigue, including brain fog, trouble concentrating, and poor memory function.²

3. Poor sleep

Poor sleep is a major contributor to fatigue. Disrupted sleep interferes with the body’s ability to regulate energy and can lead to hormonal imbalances that increase feelings of tiredness and exhaustion.

It can also exacerbate other factors associated with fatigue, such as weakened immune function, weight gain, and mood disturbances like depression, which can further reduce overall well-being.

This has been confirmed by evidence published in Sleep Science, highlighting the direct link between lack of sleep and fatigue.³

The authors conclude, “Ultimately, these findings suggest that sleep quality must be considered when trying to understand ways to improve the long-standing predisposition to energy and fatigue.”

4. Thyroid

An underactive thyroid gland is a common reason for fatigue.

Thyroid hormones are a key metabolic regulator, and disrupted thyroid function can slow down all aspects of energy production. This can lead to symptoms including fatigue, weakness, and lack of energy.

5. Low stomach acid

Stomach acid plays a vital role in digestion as it helps break down protein, enables the absorption of key vitamins and minerals, and defends the digestive tract against harmful microbes.

A condition known as hypochlorhydria, or low stomach acid, becomes increasingly common with age, particularly in individuals over 50.

When stomach acid levels are insufficient, the body may struggle to absorb nutrients like iron and vitamin B12, which are crucial for energy production.

Key takeaways

Fatigue is characterized by debilitating tiredness and persistent exhaustion. It’s a common symptom linked to various causes, including underlying medical conditions, medication use, and hormonal imbalances.

In addition, lifestyle habits, including poor diet, lack of regular exercise, and sleep issues, can cause or amplify fatigue.

Ruling out medical causes, making appropriate dietary changes, and focusing on healthy sleep are the first steps to address and combat fatigue, tiredness, and persistent lack of energy.

FAQ

1. What are the warning signs of fatigue?

Fatigue is a common symptom that can have many different causes. Some warning signs of fatigue include persistent tiredness and lack of energy, difficulty concentrating, weakness, depression, lack of motivation, and problems with memory function.

2. What are the common types of fatigue?

Some common types of fatigue include adrenal fatigue and chronic fatigue syndrome, or pathological fatigue caused by an underlying medical condition such as autoimmune disease, infection, depression, or heart disease.
Fatigue can also be a side effect of certain medications, including blood pressure medications, antihistamines, and other pharmaceutical drugs.

3. Why am I tired and have no energy?

There are many possible causes of feeling tired and having no energy. Sleep problems, chronic stress, a poor diet, and lack of physical activity are all common causes of tiredness.
Fatigue can also be a symptom of potential medical conditions, including anemia, diabetes, depression, and hypothyroidism.

4. When should you worry about fatigue?

Fatigue can have many different causes, some of which may be serious and require medical attention, and others may be due to lifestyle habits, sleep disturbances, or a poor diet.
If you have unexplained and persistent fatigue that isn’t relieved by a good night’s sleep, it’s best to consult your healthcare provider to identify potential underlying causes and explore appropriate treatment options.

5. Can keto and intermittent fasting cause fatigue?

Yes, transitioning to a ketogenic diet can cause fatigue, tiredness, and lack of energy. Keto fatigue is a temporary symptom linked to your body adjusting to burning fat instead of sugar as an energy source.
Similarly, intermittent fasting can cause temporary fatigue as it disrupts your usual eating patterns and can trigger cravings, which can result in fatigue and low energy.

6. What are the best ways to combat keto fatigue?

To combat keto fatigue, it’s essential to stay hydrated, eat plenty of nutritious keto-approved foods, and avoid strenuous physical activity until your body has fully adapted to keto.

7. How can I get rid of fatigue?

How to get rid of fatigue depends on its underlying cause. However, some general tips may help alleviate fatigue, including getting enough sleep, avoiding carbs and sugar, getting regular exercise, and finding relaxation techniques to combat stress.
If you experience unexplained fatigue, consult your doctor to identify possible medical concerns or medications that may cause your persistent tiredness and lack of energy.