Fatigue means ongoing tiredness, exhaustion, or low energy that can affect daily life. It is different from normal sleepiness after a busy day.
Common causes
Fatigue can be linked to poor sleep, stress, depression, anxiety, anemia, thyroid disease, infections, chronic pain, medications, diabetes, kidney disease, or heart and lung conditions.
Why context matters
Fatigue is a symptom, not a diagnosis. The timing, severity, associated symptoms, and medical history help guide what should be checked.
Fatigue with chest pain, severe shortness of breath, fainting, confusion, unexplained weight loss, or bleeding needs prompt medical attention.