【“Tired All the Time?” — A Symptom-Based Approach to Chronic Fatigue】　ー　Med Student's Study Room

“I’ve been feeling exhausted lately—no matter how much I sleep, it doesn’t get better.”

Fatigue is one of the most common yet challenging complaints encountered in primary care. It can arise from a wide range of causes—ranging from minor lifestyle factors to serious underlying diseases. The key lies not in finding a universal cure, but in understanding why the fatigue is happening for this specific patient.

🔎 What to Learn Today

In this article, we’ll take you through a structured clinical reasoning approach that begins with the patient’s own words and guides you step by step through history-taking, physical examination, and appropriate testing.

Understand the key causes of chronic fatigue from a differential diagnosis perspective
Master the interview process using the OPQRST + PAM HITS FOSS framework
Develop clinical eyes for subtle but meaningful signs during physical exam

Let’s begin with a typical case.

🧑‍⚕️ Case Introduction

Chief Complaint:

“I’ve been unusually tired for the past few weeks. Even after sleeping, I still feel drained.”

Patient Profile:

35-year-old woman
Vital signs: T 36.8°C, HR 82/min, BP 112/70 mmHg, SpO₂ 98%

🔍 First Impressions: How Do You Approach This Case?

When a patient complains of fatigue, your first instinct may be to ask, “Is it physical, mental, or both?” But rather than jumping to categories, try to listen closely to their story: What are they really saying? Their words often hold the first clinical clue.

This case involves a young adult with persistent fatigue that’s not relieved by sleep—a pattern lasting several weeks, which typically qualifies as chronic fatigue in the clinical context. This suggests that the underlying issue may go beyond simple overwork or lifestyle habits. But we don’t jump to conclusions yet.

One helpful strategy is to ask: “What does tired mean to you?” — Do they mean sleepy, heavy-bodied, unmotivated? This distinction often sets the direction for your differential.

At the same time, always keep red flags in mind—unintentional weight loss, low-grade fever, night sweats, or lymphadenopathy may point toward something more serious.

Let’s organize our thoughts using the FPH framework — starting with what the patient told us, and building toward a focused differential.

Understanding What “Tired” Really Means

Not all tiredness is created equal. When a patient says, “I feel tired all the time,” do they mean sleepy? Mentally drained? Physically weak?

👉 As a clinician, the first step is to clarify:

“What does tired mean to you?”

This simple question opens the door to richer diagnostic thinking. The underlying issue may be poor sleep, anemia, depression, burnout, or something else entirely.

Common Expressions and Nuances of Fatigue

Term	Nuance	Example
Tired	Temporary tiredness	“I feel tired after work.”
Fatigued	Chronic or medical fatigue	“I’ve been feeling fatigued for weeks.”
Exhausted / Drained	Extreme mental/physical burnout	“I’m mentally and physically drained.”

FPH: Structuring Clinical Thinking Around Fatigue

Let’s apply the Fact → Problem → Hypothesis framework using the case of the 38-year-old woman who reports feeling “tired all the time.”

🧩 Fact

“Lately, I feel tired no matter what I do.”
“Even after sleeping, I don’t feel refreshed.”
“I find myself zoning out at work.”

🔍 Problem (Semantic Qualifiers)

Chronic fatigue lasting for several weeks
Non-restorative sleep
Physical + mental dullness affecting daily function

👉 The key is recognizing this is not “easily tired” — it’s TATT: Tired All The Time.

🔎 Hypotheses (VITAMIN CDE Framework)

Most Likely:
Depression
Hypothyroidism
Iron deficiency anemia
Likely:
Sleep apnea
Chronic infections (e.g., TB, HIV)

🎯 What You Need to Know (NTK)

Your mission at this stage:

Prioritize hypotheses: depression, hypothyroidism, and iron deficiency anemia
Guide interview and physical exam to rule in or out these key conditions
Keep sleep quality, mental health, menstrual history, and nutrition on your radar

These NTK elements will help structure your Step 1: History Taking.

🩺 Step 1: History Taking – Structuring the Interview

In patients complaining of chronic fatigue, we begin by exploring both the nature of fatigue and the context surrounding it, using two key frameworks:

OPQRST: to understand the symptom itself
PAM HITS FOSS: to uncover contributing factors from medical, social, and psychological domains

🔍 Characterizing Fatigue – OPQRST Framework

Element	Key Questions	Purpose
O (Onset)	When did the fatigue begin? What triggered it?	Distinguish acute vs chronic (≥4 weeks)
P (Provocation/Palliation)	What makes it better or worse?	Understand context and modifiers
Q (Quality)	Is it tiredness, sleepiness, heaviness, or trouble concentrating?	Clarify the patient’s perception
R (Radiation)	Is the fatigue generalized or localized?	Screen for musculoskeletal or neurologic issues
S (Severity)	How does it affect daily life?	Assess functional impact
T (Time course)	Does it vary throughout the day? Worse in the morning or evening?	Patterns can suggest psychiatric or metabolic disorders

👉 Key distinction: Is the fatigue temporary and situational, or persistent and impairing daily function?

🧬 Exploring Contributing Factors – PAM HITS FOSS

Category	Targeted Questions
P (Past Medical History)	Thyroid disease, diabetes, sleep disorders, mental health disorders?
A (Allergies)	Any drugs that caused unusual tiredness?
M (Medications)	Current meds including antihistamines, antidepressants, beta-blockers?
H (Hospitalizations)	Recent illnesses, viral infections, or post-operative fatigue?
I (Injuries/Infections)	Any recent infections, trauma, or dental work?
T (Travel/Surgery)	Any travel, surgeries, or procedures in the last few months?
S (Stressors)	Any recent emotional stress, life events, or workload changes?
F (Family History)	Depression, autoimmune diseases, thyroid dysfunction in family?
O (Obstetric/Gynecologic)	Menstrual irregularities, heavy bleeding, perimenopausal symptoms?
S (Social History)	Smoking, alcohol, sleep-wake cycle, occupational strain?
S (Sexual History)	Risk factors for STIs, relationship-related stress?

🚩 Red Flags to Always Ask About

Unintentional weight loss
Persistent fever, night sweats, or chronic cough
Lymphadenopathy, rashes, jaundice, or bleeding tendencies
Severe mood disturbances or suicidal ideation
Infection risk factors: travel, transfusions, unprotected sex, heart murmur (IE concern)

➡️ Presence of red flags should prompt evaluation for malignancy, HIV, TB, infective endocarditis, SLE, and other systemic illnesses.

💬 Focused Questions for TATT (Tired All The Time)

💤 Sleep

“What time do you usually go to bed and wake up?”
“Do you wake up multiple times during the night?”
“Do you feel refreshed after sleep?”
“Do you feel sleepy during the day?”

(Consider the Epworth Sleepiness Scale if needed)

🧠 Mood / Life Stress

“Have you been feeling more down or hopeless lately?”
“Have you lost interest in activities you usually enjoy?”
“Have there been any major changes in your life recently (e.g., job, relationships)?”

🍽 Diet / Nutrition

“Have you noticed any changes in appetite or weight?”
“Are you following any restrictive diets?”
“What do your typical meals look like in a day?”

These targeted questions help narrow down the cause of fatigue and guide what to examine and test next. Let’s move on to Step 2: Physical Examination.

🩺 Step 2: Physical Examination – What to Look for in Fatigue

When evaluating fatigue, physical exam plays a key role in confirming or ruling out the hypotheses raised during the history. A thorough head-to-toe assessment helps identify signs of anemia, thyroid dysfunction, depression, infection, or malignancy.

👁️‍🗨️ First Impressions (Before Touching the Patient)

Observe the patient as they enter the room:

Gait: Slow, shuffling, or unstable → depression, anemia, B12 deficiency, neuromuscular disorders
Posture: Slouched, leaning on furniture → possible orthostatic intolerance, fatigue
Facial expression: Flat affect, pallor, jaundice → consider depression, anemia, liver disease
Speech: Soft, slow, delayed response → hypothyroidism, depression
Grooming: Poor hygiene or disheveled appearance → psychosocial factors

👉 Fatigue often begins with how the patient carries themselves. Clues start from the doorway.

🩺 Vital Signs and General Appearance

BP, HR, Temp, RR, SpO₂
BMI: Low in malnutrition or hyperthyroidism, high in OSA or metabolic syndrome
Overall appearance: Fatigued, lethargic, responsive? Clean or disheveled?

👀 Head and Neck

Conjunctival pallor → anemia
Scleral icterus → liver dysfunction
Facial puffiness, dry skin → hypothyroidism
Oral mucosa: Dryness (dehydration/depression), glossitis (B12 deficiency)
Thyroid exam: Goiter, nodules, tenderness
Cervical lymph nodes: Lymphadenopathy suggests infection or malignancy

🫁 Chest – Lungs and Heart

Breath sounds: Crackles (CHF, pneumonia), wheezes (asthma, COPD)
Heart sounds: Murmurs (IE), arrhythmias, distant heart sounds (pericardial effusion)

🦴 Abdomen and Extremities

Abdominal exam: Tenderness, hepatosplenomegaly, lymph nodes (inguinal)
Skin: Hyperpigmentation (Addison), ecchymoses, dryness, pallor
Hair/Nails: Hair loss (hypothyroidism), brittle nails (iron/B12 deficiency), spoon nails (koilonychia)
Joints: Swelling or tenderness (SLE, RA)

🧠 Neurologic & Mental Status

Affect: Flat, slowed movements (bradykinesia)
Speech: Coherent? Delayed?
Strength: Diffuse weakness or focal deficits?
Reflexes: Hyporeflexia (hypothyroidism), hyperreflexia (B12 deficiency)
Tremors: Fine (thyrotoxicosis), coarse (metabolic causes)

💅 Nail Signs to Watch For

Sign	Possible Cause
Spoon nails (koilonychia)	Iron deficiency anemia
Brittle/vertical ridges	Hypothyroidism, malnutrition
White nails (leukonychia)	Liver disease, low albumin
Nail pigmentation	Addison’s, drug effects
Clubbing	Lung disease, cancer
Pale nail beds	Anemia, poor circulation

🧩 Summary of Key Findings

Sign/Pattern	Interpretation
Pale conjunctiva	Suggests iron deficiency anemia
Diffuse goiter + dry skin + edema	Consistent with hypothyroidism
Heart murmur + fever + lymphadenopathy	Consider infective endocarditis
Flat affect, slowed movements	Supports depression
No focal findings	Psychosocial or functional fatigue more likely

➡️ Let’s move forward to Step 3: Investigations, to support or rule out these clinical impressions.

🧪 Step 3: Investigations – What to Order for Fatigue

After completing the history and physical examination, the next step is to perform targeted investigations. These help to confirm your top differential diagnoses or rule out serious underlying conditions.

🎯 Goals of Investigation

Support or confirm suspected conditions (e.g., iron deficiency, hypothyroidism)
Exclude red flags such as infections, malignancy, or autoimmune diseases
Conduct a broad screening when the cause of fatigue remains unclear

🧪 Core Laboratory Tests

Test	Purpose
CBC	Identify anemia, leukocytosis (infection), thrombocytopenia
TSH, FT4	Assess thyroid function, screen for hypothyroidism
HbA1c, Fasting glucose	Evaluate for diabetes or hypoglycemia
Electrolytes (Na, K, Ca, Mg)	Detect adrenal, renal, or metabolic imbalances
Liver and renal panels	Assess for liver or kidney dysfunction
CRP, ESR	Detect chronic inflammation or underlying infection
BNP/NT-proBNP	Consider in cases with dyspnea or suspected heart failure

🧪 Additional Tests Based on Clinical Suspicion

Test	Indications
Ferritin, Fe, TIBC	Suspected iron deficiency anemia
Vitamin B12, Folate	Neurological symptoms or macrocytic anemia
Morning cortisol	Possible adrenal insufficiency
CK (Creatine Kinase)	Myopathy, statin use, or muscle-related symptoms
Vitamin D	Chronic fatigue, especially with mood changes
PHQ-9 / Whooley questions	Screening for depression
HIV, HBV, HCV antibodies	Risk factors for chronic viral infections
ANA, RF, anti-CCP	Suspected autoimmune disease (e.g., SLE, RA)
tTG-IgA / total IgA	Celiac disease screening in nutritional deficiencies

😴 Sleep Evaluation (If Indicated)

Epworth Sleepiness Scale: For daytime somnolence or suspected OSA
Polysomnography (PSG): Refer when sleep apnea or parasomnia is likely

🧫 Urine and Stool Tests

Urinalysis: Evaluate for renal disease, glycosuria, or hematuria
Fecal occult blood / stool culture: If chronic blood loss or GI infection is suspected

📷 Imaging Studies

Study	Indications and Goals
Chest X-ray (CXR)	Screen for malignancy, chronic infection, or cardiomegaly
Thyroid ultrasound	Evaluate goiter, nodules, or thyroiditis
Abdominal ultrasound	Hepatosplenomegaly, masses; may be done via POCUS
Echocardiography (TTE/POCUS)	Assess LV function, pericardial effusion, endocarditis signs
Lung ultrasound	Look for pleural effusion, B-lines, or interstitial changes
IVC ultrasound	Estimate intravascular volume status

🧩 Interpretation of Common Findings

Result Pattern	Interpretation
Low Hb + low MCV + low ferritin + high TIBC	Consistent with iron deficiency anemia
Elevated TSH + low FT4 + positive anti-TPO	Suggestive of Hashimoto’s thyroiditis
Normal labs + elevated PHQ-9	Depression likely contributor
CRP elevated + heart murmur + anemia	Consider infective endocarditis
All tests within normal range	Suspect psychosocial fatigue; re-evaluate context

With the lab and imaging data in hand, we’re now ready to return to our patient case and apply this information in a structured clinical reflection.

🩺 Case Reflection – Applying Step 1–3 to the Patient

Now that we’ve reviewed the core approach from Step 1 (history) to Step 3 (investigations), let’s apply what we’ve learned to the case presented at the beginning.

🚪 Doorway Information

Age/Sex: 34-year-old female
Chief Complaint: “I’ve been feeling exhausted all the time. It’s especially bad in the morning.”
Vitals: BP 110/70 mmHg, HR 78 bpm, Temp 36.5°C, SpO₂ 98%, RR 14/min

🎯 Need To Know (NTK)

Duration and pattern of fatigue
Sleep quality, mood, stressors, appetite, weight change
Menstrual history, dietary habits, medication use
Risk factors for infection or autoimmune disease

🗣️ Step 1: History Review (Fact → Problem → Hypothesis)

Fact (from patient interview):

Fatigue for about 3 weeks, worse in the morning, persistent throughout the day
Waking up multiple times at night, not feeling refreshed
Increased work stress and poor relationship with new supervisor
2 kg weight loss in the past month
Regular menstruation, but heavy bleeding; history of anemia

Problem (semantic qualifiers):

Persistent fatigue without diurnal variation
Non-restorative sleep (frequent awakenings)
Psychosocial stressors (work-related)
Potential iron deficiency (heavy menses, weight loss)

Hypotheses (Top 3):

Depression – sleep disturbance, psychosocial stress, reduced concentration
Iron deficiency anemia – fatigue, menorrhagia, pale appearance, history of anemia
Hypothyroidism – chronic fatigue, poor-quality sleep, possible thyroid enlargement

🧑‍⚕️ Step 2: Physical Examination Review

Observed findings:

Slouched posture, slow movement, low-volume voice, fatigued expression
BMI slightly low; vital signs stable
Pale conjunctivae, no scleral icterus
No facial edema or dryness; no significant hair loss or swelling
Mild diffuse thyroid enlargement, non-tender, no nodules
Heart and lung exams normal; no murmurs, lymphadenopathy, or abnormal breath sounds
Abdomen soft, non-tender; no organomegaly
Skin intact; no rash or petechiae
Nails brittle with vertical ridges

Summary of findings:

🟢 Flat affect, bradykinesia
🟢 Pale conjunctivae
🟡 Mild goiter without nodules
🟢 Brittle nails (possible nutritional deficiency)

Working Hypotheses After Exam:

Iron deficiency anemia supported by pale conjunctivae and brittle nails
Subclinical hypothyroidism possible with goiter, fatigue, and mood symptoms
Depression consistent with affect, posture, and psychosocial background
No signs suggestive of acute infection, malignancy, or autoimmune disease

🧪 Step 3: Investigations Review

Category	Test	Result	Interpretation
Anemia workup	Hb	10.5 g/dL	Low – indicates anemia
	MCV	72 fL	Microcytic
	Ferritin	8 ng/mL	Very low – supports iron deficiency
	TIBC	410 μg/dL	Elevated – confirms iron-deficiency pattern
Thyroid	TSH	4.9 μIU/mL	Mildly elevated
	FT4	0.9 ng/dL	Low-normal
	POCUS	Mild goiter, no nodules, mild hypervascularity
Inflammation	CRP	0.2 mg/dL	Normal
	WBC	6,300 /μL	Normal
Nutrition	Vit B12	520 pg/mL	Normal
	Na / Ca / Mg	139 / 9.1 / 1.9	Normal
Screening	CXR	No abnormalities	No malignancy or infection signs
	Urinalysis	Negative	Normal
Psychiatric	PHQ-9	8 points	Mild depression possible

Interpretation:

Iron deficiency anemia is confirmed
Subclinical hypothyroidism suspected (TSH mildly elevated with low-normal FT4)
Mild depressive symptoms also likely contribute
No signs of infection, inflammation, malignancy, or autoimmune disorder

✅ Final Assessment

Primary Diagnosis:

Iron deficiency anemia – consistent with fatigue, microcytic anemia, low ferritin, history of heavy menses

Contributing Factors:

Subclinical hypothyroidism – possible contributor; monitor over time
Psychosocial stress and sleep disturbance – likely exacerbating symptoms

📋 Plan

Treat iron deficiency:

Start oral iron therapy (e.g., ferrous fumarate 50 mg BID)
Provide dietary advice (increase iron-rich foods)
Monitor GI side effects and adherence

Monitor thyroid function:

No immediate treatment needed
Recheck TSH and FT4 in 3–6 months
Consider anti-TPO Ab if not yet done

Support mental health:

Continue follow-up and monitor PHQ-9
Encourage open discussion of stressors
Refer to mental health if symptoms worsen

Lifestyle guidance:

Sleep hygiene counseling
Light physical activity
Structured daily routine

Follow-up:

Reassess fatigue and labs in 2–4 weeks
Adjust management depending on response

🧑‍⚕️ When to Refer to Specialists – Red Flags and Referral Triggers

While most cases of fatigue can be managed in primary care, certain findings should prompt referral to specialists. Timely consultation ensures accurate diagnosis, comprehensive evaluation, and optimal patient care.

🧠 Referral to Psychiatry

Refer to mental health services when:

PHQ-9 score ≥ 10, or suicidal ideation is present
Functional impairment due to depressive symptoms
No improvement with initial supportive interventions

🧬 Referral to Endocrinology

Consider endocrinology referral when:

TSH remains elevated with low FT4 (clinical hypothyroidism)
Presence of goiter with compressive symptoms or nodules
Suspicion of autoimmune thyroiditis (e.g., positive anti-TPO Ab)

🩸 Referral to Hematology

Refer for further evaluation when:

Severe anemia (Hb < 8.0 g/dL)
Suspicion of GI blood loss (e.g., positive fecal occult blood)
Anemia with unclear etiology or unresponsive to iron therapy
Pancytopenia or abnormal peripheral smear

🧪 Suggested Pre-Referral Workup

Before referral, it’s helpful to complete the following:

CBC with differential, ferritin, Fe/TIBC
TSH, FT4, ± anti-TPO Ab
CRP, ESR
PHQ-9 or other depression screeners
Chest X-ray, urinalysis
Fecal occult blood test if bleeding suspected

📝 Referral Summary Tips

When writing a referral, include:

Chief complaint and duration
Key findings from history and physical exam
Relevant lab/imaging results
Working diagnosis or suspected condition
Specific concerns or questions for the consultant

➡️ A concise and informative referral letter facilitates efficient care coordination and helps the specialist focus on your clinical questions.

🧠 Clinical Tips – Interviewing and Examining the Fatigued Patient

Fatigue is a common but often vague complaint. Sharpening your approach to history taking and physical examination can significantly improve diagnostic accuracy.

🗣️ Interviewing Tips (History Taking)

Use Silence Strategically:

Let the patient pause; the truth often follows a moment of hesitation.

Clarify the ‘Type’ of Fatigue:

“Is it sleepiness, a heavy body, difficulty focusing, or just a general lack of energy?”

Explore Daily Routine:

“What time do you go to bed and wake up? What’s your morning like?”

Reflect Patient’s Words:

“You mentioned feeling ‘worn out’ — can you describe what that feels like for you?”

Incorporate Screening Naturally:

“Have you found less joy in things you used to enjoy?”
“Any changes in your appetite or weight recently?”

🧑‍⚕️ Physical Exam Tips

Observe at Entry:

Gait speed, posture, and whether they lean on furniture provide subtle diagnostic cues.

Facial and Vocal Cues:

Blunted affect or flat tone may suggest mood disorders or hypothyroidism.

Check the Eyes and Nails:

Pale conjunctivae → anemia
Brittle or spoon-shaped nails → iron deficiency or malnutrition

Always Palpate the Thyroid:

Many cases of goiter are asymptomatic and underrecognized.

Look for Subtle Skin Clues:

Dry skin, pigmentation changes, or easy bruising can hint at endocrine or systemic illness

Don’t Just Hunt for Abnormalities:

A normal exam can be just as informative — ruling out red flags builds diagnostic confidence.

Taking fatigue seriously means listening beyond the words and observing beyond the numbers. Use these tips to extract critical insights from subtle clinical clues.

💡 Clinical Pearls

“Fatigue is the price we pay for adaptation.”
— Hans Selye (Founder of Stress Theory)

“Exhaustion doesn’t mean weakness — it may mean persistence.”

These reflections remind us that fatigue is not always pathology — it can be a story of resilience, stress, and silent struggle. Listen carefully to what’s not said.

✉️ OET Writing Practice – Referral Letter Essentials

If you are preparing for the OET (Occupational English Test), writing an effective referral letter is key. Here’s a sample structure and tips based on our fatigue case:

📄 Referral Letter Template (Fatigue Case)

Introduction:

I am writing to refer Ms. Jane Smith, a 34-year-old woman who presents with persistent fatigue over the past three weeks.

Background:

She reports non-restorative sleep, reduced concentration, and recent psychosocial stress following a change in her workplace environment.

Relevant Findings:

Physical examination revealed pale conjunctivae and mild goiter. Blood tests confirmed iron deficiency anemia and subclinical hypothyroidism.

Purpose of Referral:

I would appreciate your assessment regarding further evaluation and management of her thyroid dysfunction and to consider whether psychiatric support may be beneficial.

Closing:

Please do not hesitate to contact me for any further information.

Kind regards,
[Your Name]
[Your Clinic/Practice]

📝 Writing Tips for OET

Stay objective, concise, and professional
Use past medical events in chronological order
Highlight clinical relevance (not every lab value)
Avoid personal opinions; keep tone neutral and factual

Practicing referral letters like this one will strengthen your real-world communication and help you succeed in the OET writing subtest.

🗣️ OET Speaking – Useful Expressions for Fatigue Cases

In the OET Speaking subtest, you may need to explain a diagnosis, reassure a patient, or respond to concerns. Here are expressions tailored to fatigue-related cases:

🧾 Explaining Diagnoses in Simple Terms

“Iron deficiency anemia means your body doesn’t have enough iron to make healthy red blood cells, which carry oxygen.”
“Subclinical hypothyroidism is a mild form of low thyroid function. It may contribute to your tiredness.”
“Chronic fatigue can sometimes be linked to stress, poor sleep, or emotional health.”

🤝 Reassuring the Patient

“I understand that feeling tired all the time is frustrating, but we’ll work together to find the cause and help you feel better.”
“Many people experience this, and we have effective ways to manage it.”
“You’re not alone. We’ll follow up regularly and adjust treatment as needed.”

❓ Responding to Challenging Questions

Patient: “Is this something serious? Could it be cancer?”

“Based on your tests and physical exam, there’s no sign of anything serious like cancer. We’ll continue monitoring just to be sure.”

Patient: “Why am I still tired even though I sleep a lot?”

“That’s a good question. Sometimes the quality of sleep is more important than the number of hours. We’ll look into your sleep patterns further.”

Patient: “Do I need to take medicine for this forever?”

“In most cases, treatment is short-term. We’ll start with what’s necessary and reassess based on how you respond.”

💬 Encouraging Self-Care and Follow-Up

“Try to maintain a regular sleep schedule, balanced diet, and light exercise — these can really help.”
“Let’s check back in a few weeks to see how things are going.”

These expressions demonstrate empathy, clear communication, and clinical professionalism — all key aspects evaluated in the OET Speaking subtest.

🧾 Final Thoughts – Wrapping Up the Fatigue Case

Fatigue is a common yet complex symptom that can mask a wide array of underlying conditions—from lifestyle-related causes to serious systemic illnesses. As we’ve explored in this article, a structured approach beginning with careful history-taking (OPQRST + PAM HITS FOSS), followed by targeted physical examination and reasoned investigation, is essential to reach the correct diagnosis.

Stay curious, keep practicing, and continue developing both your clinical and communication skills. See you in the next case!

🔗 Related Articles – Explore More Symptom-Based Cases

😵‍💫 Fatigue – You’re here!
💔 Palpitations: A Symptom-Based Clinical Approach
💨 Symptom-Based Approach: Pleural Effusion
🧠 How to Approach Memory Loss: Is It Just Aging, or Something More?
🩺 “I’ve Been Losing Weight…”—Is It Really Diet Success?
🩸 🩺 Hypovolemia: Clinical Clues to Catch Before the Collapse
日本語版はこちら：😵‍💫 疲れがとれない？全身倦怠感に潜む16の疾患とその見分け方
Mock case drills: 🩺 Mock Patient Scripts

📚 References – Sources Cited

Kroenke K, Wood DR, Mangelsdorff AD, Meier NJ, Powell JB. Chronic fatigue in primary care. Prevalence, patient characteristics, and outcome. JAMA. 1988;260(7):929–934.
Fukuda K, et al. The chronic fatigue syndrome: a comprehensive approach to its definition and study. Ann Intern Med. 1994;121(12):953–959.
Sharpe M, Wilks D. Fatigue. BMJ. 2002;325(7362):480–483.
Bensing J, Verhaak P, van Dulmen S, Visser A. Communication with the patient in the general practitioner’s consultation. Patient Educ Couns. 2000;39(1):1–8.