What is Chronic Fatigue: When Tiredness Doesn’t Lift?

What chronic fatigue is, how it differs from normal tiredness, and how it is assessed and managed.

General Health

Chronic Fatigue: When Tiredness Doesn’t Lift

2025-11-18

Intro

Chronic fatigue is persistent, often disabling tiredness that does not improve with rest and significantly limits day-to-day life. It is a symptom that can arise from many different conditions, including infections, mood disorders, hormonal problems, and chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME).

Key Points

Fatigue is common and usually short-lived; chronic fatigue lasts ≥3–6 months.
Many medical and psychological conditions can cause chronic fatigue.
Evaluation looks for reversible causes (sleep, anaemia, thyroid, mood, medications, infection, etc.).
Specific criteria apply for chronic fatigue syndrome/ME.
Management focuses on treating underlying causes, pacing, sleep, and mental health support.

Background

Fatigue sits on a spectrum from “a bit tired” to “cannot get out of bed.” Persistent fatigue deserves a structured assessment, especially if it interferes with work, relationships, or basic self-care.

Causes or Mechanisms

Common contributors include:

Sleep problems (insomnia, sleep apnoea)
Mood disorders (depression, anxiety)
Endocrine and metabolic problems (thyroid disease, diabetes)
Anaemia, chronic infection, inflammatory conditions
Medications, alcohol, and drugs
Post-infectious states (including long COVID and PTLDS in some patients)

Diagnosis / Treatment / Options

Assessment usually includes:

History, examination, basic blood tests
Screening for sleep, mood, medications, and substance use
Considering red flags (weight loss, fever, night sweats, etc.)

Treatment is tailored: correct reversible causes, address sleep, gently rebuild activity, treat mood disorders, and provide psychological support.

Risks / Benefits / Prognosis

Many causes of fatigue improve with treatment, but some post-infectious and chronic conditions can be prolonged. A supportive clinician, realistic pacing, and avoiding boom–bust cycles help long-term outcomes.

FAQ

Q: Is chronic fatigue the same as CFS/ME?
A: No. CFS/ME is a specific diagnosis with defined criteria. Chronic fatigue is a broader symptom category.

Q: Can infections like Lyme or COVID lead to long-term fatigue?
A: Yes, post-infectious fatigue is recognised after several infections, including Lyme disease and COVID-19.