What is a fatigue that comes and goes?

September 30, 2025 •

4 min read

According to the National Institute on Aging, fatigue can signal a more serious underlying medical or mental health condition than a simple lack of sleep. Understanding what is a fatigue that comes and goes—and its potential causes—is the first step toward finding relief from these often-debilitating episodes of exhaustion.

Quick Summary

This article explores the nature of intermittent fatigue, its possible links to underlying conditions such as ME/CFS and autoimmune disorders, and various lifestyle and medical strategies for effective management. It highlights the importance of working with a healthcare provider for diagnosis.

Key Points

Understanding the pattern: A fatigue that comes and goes is characterized by cycles of debilitating exhaustion and normal energy levels, unlike simple tiredness.
Investigate chronic conditions: Fluctuating fatigue is a core symptom of serious conditions like ME/CFS, autoimmune diseases (lupus, MS), thyroid disorders, and POTS.
Address lifestyle factors: Poor sleep hygiene, inadequate hydration, nutrient deficiencies, and emotional stress are common, modifiable causes of intermittent fatigue.
Implement pacing strategies: Scheduling rest periods and breaking down activities can prevent triggering post-exertional malaise (PEM), a hallmark of ME/CFS that exacerbates fatigue.
Seek medical diagnosis: It is critical to consult a healthcare provider to rule out underlying medical issues with blood tests and physical examinations.
Manage with mind and body: A combination of stress management techniques, gentle exercise, and a balanced diet can help stabilize energy levels.

A fatigue that comes and goes, also known as intermittent or fluctuating fatigue, is a distinct symptom characterized by periods of profound exhaustion alternating with periods of relative normalcy. This is different from normal, temporary tiredness that is resolved by rest. For those who experience it, this unpredictable cycle can be highly disruptive to daily life, making it difficult to plan activities, maintain a work schedule, and manage personal and social responsibilities. While it can be challenging to pinpoint the exact cause, many contributing factors—ranging from lifestyle issues to chronic medical conditions—can be responsible.

Understanding Intermittent Fatigue

Unlike the simple weariness that follows a long day, intermittent fatigue is a persistent and often overwhelming exhaustion. During a 'relapse' or 'flare-up,' a person may feel completely drained, experiencing a significant reduction in their ability to perform their usual daily activities. This is a core symptom of conditions such as Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), where post-exertional malaise (PEM) causes symptoms to worsen dramatically after even minimal physical or mental effort. For others, the fluctuations might be tied to sleep patterns, stress levels, or dietary habits. The unpredictable nature of this type of fatigue is often as distressing as the exhaustion itself.

Common Causes of Fluctuating Fatigue

Several potential causes can contribute to a fatigue that comes and goes, and it is important to consider all possibilities with a healthcare provider to receive an accurate diagnosis.

Chronic Conditions

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A long-term illness with a hallmark symptom of severe fatigue that lasts over six months and is not relieved by rest. Symptoms, including pain, unrefreshing sleep, and cognitive problems, can come and go in cycles.
Autoimmune Disorders: Conditions such as lupus, multiple sclerosis (MS), and rheumatoid arthritis can cause fatigue due to inflammation. Symptoms of these conditions often wax and wane, leading to fluctuating energy levels.
Thyroid Problems: An underactive thyroid (hypothyroidism) can cause a metabolic slowdown that results in chronic fatigue and tiredness. A blood test can help diagnose this issue.
Diabetes: Poorly managed blood sugar levels in both type 1 and type 2 diabetes can lead to fluctuating energy levels.
Heart and Lung Conditions: Heart failure and Chronic Obstructive Pulmonary Disease (COPD) can cause fatigue due to reduced oxygen circulation.
Postural Orthostatic Tachycardia Syndrome (POTS): This autonomic nervous system disorder can cause extreme, on-and-off fatigue that is often accompanied by dizziness and brain fog.

Sleep Disorders and Mental Health

Sleep Apnea: Repeatedly interrupted breathing during sleep leads to poor sleep quality and can cause severe daytime fatigue.
Insomnia: Difficulty falling or staying asleep can obviously result in chronic tiredness.
Depression and Anxiety: Mental health struggles can manifest physically, with fatigue being a common symptom. Chronic stress keeps the body in a high-alert state, which is incredibly draining.

Other Factors

Infections: Post-viral fatigue, including lingering fatigue from COVID-19, is a recognized phenomenon.
Nutrient Deficiencies: A lack of certain vitamins and minerals, particularly iron and vitamin D, can cause anemia and subsequent energy loss.
Lifestyle and Diet: Poor diet, inadequate hydration, too much or too little exercise, and excessive caffeine or alcohol consumption can all lead to energy fluctuations.

Managing Fatigue That Comes and Goes

Managing fluctuating fatigue often involves a combination of lifestyle adjustments and, when necessary, medical intervention. Keeping a fatigue diary can be a useful tool for identifying personal triggers and patterns.


Strategy	Focus	Implementation	Potential Benefits
Pacing	Activity planning	Break down tasks, schedule rest, avoid overexertion.	Reduces the severity and frequency of post-exertional malaise.
Sleep Hygiene	Rest quality	Maintain a consistent sleep schedule, create a dark/cool/quiet bedroom.	Improves restorative sleep and overall energy levels.
Nutritional Support	Diet and hydration	Consume a balanced diet, prioritize whole foods, stay hydrated.	Provides steady energy and addresses potential deficiencies.
Stress Management	Mental well-being	Practice relaxation techniques like mindfulness, yoga, or meditation.	Lowers overall stress load and helps manage anxiety.
Gentle Exercise	Physical activity	Engage in low-impact activities like walking or stretching, and build up gradually.	Boosts energy levels and improves mood without causing a crash.
Medical Treatment	Underlying cause	Consult a doctor for tests and discuss potential medications or therapies.	Addresses root cause of fatigue, such as anemia or a thyroid disorder.

The Importance of Professional Guidance

While lifestyle changes can significantly help, it is crucial to see a healthcare provider if you experience persistent or fluctuating fatigue. A doctor can help rule out underlying medical conditions through examinations and lab tests. For example, a simple blood test can check for anemia or thyroid issues. Discussing your symptoms with a professional ensures you receive the correct diagnosis and treatment plan, which is essential for safely and effectively managing your energy levels and improving your quality of life.

Conclusion

Experiencing a fatigue that comes and goes is a challenging but manageable health issue once the root cause is identified. By carefully observing patterns, implementing targeted lifestyle strategies like pacing and proper nutrition, and seeking professional medical advice, individuals can regain more control over their energy levels. Patience and a proactive approach are key to navigating the unpredictable nature of this condition and reducing its impact on everyday life.

For more information on chronic fatigue syndrome, consider visiting the official Mayo Clinic page on the topic.(https://www.mayoclinic.org/diseases-conditions/chronic-fatigue-syndrome/symptoms-causes/syc-20360490)

Frequently Asked Questions

Normal tiredness is typically a short-term, manageable feeling of drowsiness that resolves with a good night's sleep. Intermittent fatigue, however, is a persistent and often severe exhaustion that comes and goes, is not significantly alleviated by rest, and can severely interfere with daily activities.

Yes, fluctuating fatigue can be a symptom of a wide range of serious medical conditions. Examples include autoimmune disorders like lupus and rheumatoid arthritis, heart disease, diabetes, and neurological diseases like multiple sclerosis.

If you wake up feeling unrefreshed despite getting a full night's sleep, or if your sleep is frequently interrupted by snoring or pauses in breathing, a sleep disorder like sleep apnea may be the cause. A doctor may recommend a sleep study for a proper diagnosis.

PEM is a condition where symptoms of fatigue and illness worsen after even minor physical or mental activity, and it can last for more than 24 hours. It is a key diagnostic feature of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Lifestyle factors such as poor diet, dehydration, an inconsistent sleep schedule, and too much or too little exercise can significantly impact energy levels and exacerbate intermittent fatigue. Stress and high caffeine intake can also contribute to the cycle.

It is highly recommended to see a doctor if your fatigue lasts longer than a few days, comes on suddenly, or is accompanied by other symptoms like pain, dizziness, or a fever. A professional can help rule out serious medical causes and provide an effective management plan.

Managing energy is best achieved through 'pacing,' which involves planning activities and incorporating rest to avoid overexertion. This can be supported by adopting good sleep hygiene, eating a healthy diet, and practicing stress reduction techniques.