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Introduction
What does persistent fatigue mean?
Fatigue is an ongoing feeling of tiredness, exhaustion, or low energy. Occasional tiredness may improve with rest, but fatigue lasting longer than two weeks, becoming worse, or interfering with daily activities should generally be discussed with a healthcare provider.
Is Fatigue Different From Feeling Sleepy?
Fatigue, sleepiness, and muscle weakness are related but different symptoms.
- Fatigue is a lack of energy or a feeling of exhaustion.
- Sleepiness means having difficulty staying awake.
- Muscle weakness is a loss of physical strength or difficulty using a muscle normally.
Describing the feeling accurately can help your doctor narrow down its possible causes. For example, waking up unrefreshed may point toward a sleep concern, while shortness of breath during routine activity may require a different evaluation.
What Are the Main Causes of Fatigue?
There is no single cause of fatigue. It can be related to everyday habits, emotional well-being, medication, or a medical condition. In some cases, several factors contribute at the same time.
1. Poor or Disrupted Sleep
Not getting enough good-quality sleep is one of the most common reasons people feel tired. Possible contributors include:
- An inconsistent sleep schedule
- Shift work
- Insomnia
- Pain that interrupts sleep
- Screen use late at night
- Caring for a baby or family member
- Environmental noise or light
Sleep disorders can also cause persistent fatigue. For example, obstructive sleep apnea may repeatedly interrupt breathing during sleep.
Possible signs include loud snoring, gasping or choking during sleep, morning headaches, and feeling unrefreshed despite spending enough time in bed.
2. Stress and Mental Health Concerns
Prolonged stress can be physically and mentally exhausting. Anxiety may make it difficult to relax or sleep, while depression can cause low energy, changes in sleep, difficulty concentrating, and loss of interest in usual activities.
These symptoms deserve the same attention as physical causes of fatigue. Speak with a healthcare provider if fatigue occurs with persistent sadness, hopelessness, anxiety, or reduced interest in activities you normally enjoy.
3. Viral Infections and Recovery From Illness
Many infections can cause fatigue while the immune system responds to illness. Low energy may continue for a period after other symptoms improve.
The pattern and duration can vary depending on the illness and the individual. Seek medical advice if fatigue following an infection is severe, continues to worsen, or significantly limits your normal activities.
4. Anemia and Nutritional Deficiencies
Anemia occurs when the blood cannot carry oxygen as effectively as it normally does. Iron deficiency is one possible cause, although anemia can have many explanations.
In addition to fatigue, anemia may cause:
- Weakness
- Dizziness or light-headedness
- Shortness of breath with activity
- Headaches
- A fast heartbeat
- Pale skin
Low levels of nutrients such as iron or vitamin B12 may contribute to fatigue in some people. Do not assume that fatigue means you need a supplement. Taking iron without appropriate assessment may be unnecessary or harmful, and the reason for a deficiency may require investigation.
5. Thyroid and Other Metabolic Conditions
The thyroid gland helps regulate how the body uses energy. An underactive thyroid may cause fatigue along with symptoms such as feeling cold, dry skin, constipation, weight changes, or difficulty concentrating.
Diabetes can also contribute to tiredness, particularly when blood glucose levels are outside an individual’s target range. Increased thirst, frequent urination, blurred vision, or unexplained weight changes should be discussed with a healthcare provider.
6. Medication and Substance Effects
Prescription medications, over-the-counter products, and natural health products can sometimes cause fatigue. Examples may include certain allergy medicines, sleep aids, blood pressure medicines, and medications used for anxiety or depression.
Alcohol, cannabis, nicotine, and high caffeine intake may also affect sleep quality and daytime energy. Never stop a prescribed medication suddenly. A physician or pharmacist can review your medication list and discuss whether changes are appropriate.
7. Lifestyle and Nutrition Factors
Irregular meals, dehydration, prolonged inactivity, overtraining, and demanding work schedules can all contribute to low energy. Large amounts of caffeine may provide short-term alertness but can interfere with sleep and contribute to an ongoing cycle of fatigue.
Improving sleep habits, eating regular balanced meals, staying hydrated, and gradually returning to physical activity may help when fatigue is mild. Some patients may also benefit from professional nutrition counselling, based on their individual needs. Persistent symptoms still warrant assessment.
8. Chronic or Complex Medical Conditions
Fatigue may occur with heart, lung, kidney, liver, autoimmune, inflammatory, or other chronic conditions. It does not mean that a person necessarily has one of these conditions, but ongoing or unexplained fatigue should not be diagnosed through symptoms alone.
A family physician can assess the overall pattern and determine whether further investigation or specialist input is clinically appropriate.
When Should You See a Doctor for Fatigue?
Consider making a medical appointment when fatigue:
- Lasts longer than two weeks
- Is becoming more frequent or severe
- Does not improve with adequate sleep and basic self-care
- Interferes with work, school, exercise, or daily responsibilities
- Begins after starting a medication or changing a dose
- Occurs with fever, rash, pain, or recurrent infections
- Occurs with unexplained weight loss
- Is accompanied by increased thirst or frequent urination
- Occurs with heavy menstrual bleeding or other possible blood loss
- Is associated with persistent low mood, anxiety, or loss of interest
- Causes you to limit your normal activities
Canadian patient guidance recommends medical assessment when fatigue persists beyond two weeks or affects daily functioning. Contact a healthcare provider sooner if symptoms are worsening or you have an existing condition that may increase your health risks. (HealthLink BC, MyHealth Alberta)
When Is Fatigue an Emergency?
Fatigue by itself is not usually an emergency. Call 911 or go to the nearest emergency department if sudden or severe fatigue occurs with:
- Chest pain or pressure
- Severe difficulty breathing
- Fainting or loss of consciousness
- New confusion or significantly reduced alertness
- Sudden weakness or numbness on one side
- Trouble speaking, seeing, walking, or maintaining balance
- A seizure
- A severe headache with a stiff neck
North East Medical Clinic does not provide emergency services. Health Link Alberta can be reached at 811 for non-emergency health advice when you are unsure where to seek care. (North East Medical Clinic)
What Can a Doctor Check During a Fatigue Assessment?
A fatigue assessment usually begins with a discussion of:
- When the fatigue started and how it has changed
- Sleep quality and sleep schedule
- Diet, physical activity, work, and stress
- Recent illnesses
- Menstrual or other bleeding history, when relevant
- Mental health symptoms
- Prescription medicines, supplements, and other substances
- Existing medical conditions
- Symptoms such as pain, fever, weight change, breathlessness, or
heart palpitations
A physical examination and diagnostic tests may be recommended based on the clinical assessment. Testing is individualized; not everyone with fatigue requires the same blood work or investigations.
Could You Need an Internal Medicine Referral?
Most people can begin by discussing fatigue with a family physician or primary care provider. If the symptoms involve a complex condition, several body systems, or multiple chronic health concerns, the physician may consider an internal medicine referral.
At North East Medical Clinic, internal medicine services are provided by referral only and depend on clinical appropriateness and specialist availability. Care may be coordinated with the patient’s primary care provider. (Internal Medicine Services)
How to Prepare for Your Appointment
Before your visit, consider keeping a brief symptom record that includes:
- When you feel most tired
- How many hours you sleep
- Whether sleep feels restorative
- Symptoms that occur with the fatigue
- Recent illness or life changes
- Medication or supplement changes
- How fatigue affects your usual activities
Bring an up-to-date list of medications and supplements. These details can help your physician understand the pattern and decide what evaluation may be appropriate.
Speak With a Family Physician in Northeast Calgary
If ongoing fatigue is affecting your daily life, a family physician can review your symptoms, health history, sleep, medications, and other possible contributing factors.
North East Medical Clinic provides family practice and primary care in Northeast Calgary based on physician availability and clinical assessment. Referrals and follow-up care may be arranged when clinically appropriate. Call (587) 393-6633 or request a non-urgent appointment. Do not include detailed medical information in the online booking form.
Questions patients ask
Frequently Asked Questions
What is the most common cause of fatigue?
Poor sleep, stress, illness, medication effects, and lifestyle factors are common causes. Fatigue can also be associated with anemia, thyroid disorders, diabetes, mental health concerns, or other medical conditions. The cause cannot be determined from fatigue alone.
How long is too long to feel fatigued?
Fatigue that lasts longer than two weeks, worsens, or affects your ability to complete normal activities should generally be assessed by a healthcare provider.
What blood tests are used to investigate fatigue?
The appropriate tests depend on a person’s symptoms, medical history, medications, and examination. A physician may consider tests related to blood cells, iron, thyroid function, blood glucose, or other areas, but no single standard panel is suitable for everyone.
Can low iron cause fatigue?
Iron deficiency and iron-deficiency anemia can cause fatigue, weakness, dizziness, or shortness of breath. These symptoms have many possible causes, so speak with a healthcare provider before starting iron supplements.
Can stress make you feel physically exhausted?
Yes. Ongoing stress and anxiety can affect sleep, concentration, appetite, and energy. Depression can also cause persistent fatigue. A healthcare provider can assess both physical and emotional contributors.
Should I see a family doctor or an internal medicine specialist?
A family physician is usually the appropriate first point of contact. An internal medicine referral may be considered when fatigue is connected to a complex, chronic, or multi-system medical concern. Specialist services at North East Medical Clinic require a referral.
Medical information: This article is educational and does not replace individualized medical advice. Services depend on clinical assessment, physician availability, and referral requirements where applicable.