Persistent Fatigue After Holiday May Signal Chronic Fatigue Syndrome

Feeling sluggish for a day or two after a long holiday is natural. The concern arises when fatigue persists for days without improvement.

If adequate sleep fails to refresh you, light activity triggers exhaustion, and concentration at work or school noticeably declines, you should suspect chronic fatigue syndrome rather than simple post-holiday malaise.

According to medical experts on May 20, chronic fatigue syndrome refers to a condition where clinically unexplained fatigue persists or recurs for six or more months without an identifiable underlying disease, severely disrupting daily life.

While ordinary fatigue recovers with rest, chronic fatigue syndrome does not improve after rest and characteristically worsens with mental or physical activity. Non-restorative sleep—waking up without feeling refreshed—recurs, and some patients experience dizziness, heart palpitations, and impaired memory and concentration.

If no signs of recovery appear several days after the holiday ends, self-assessment is necessary. The key is returning to pre-holiday routines. Minimizing the gap between weekday and weekend sleep schedules and limiting naps helps maintain nighttime sleep quality. Rushing into strenuous exercise should also be avoided.

"Post-holiday fatigue usually improves once daily rhythms are restored, but if fatigue continues to disrupt daily life after a certain period—combined with post-activity worsening, non-restorative sleep, and cognitive or autonomic symptoms—it may signal chronicity," said Kim Yang-hyun, professor of family medicine at Korea University Anam Hospital. "Realigning circadian rhythms through daytime sunlight exposure and blocking artificial light at night, along with light exercise, helps restore vitality."

If fatigue persists despite lifestyle improvements or symptoms such as poor concentration continue, visiting a medical facility to identify the cause is advisable. Basic blood tests can screen for underlying conditions including anemia, thyroid dysfunction, liver function abnormalities, kidney function issues, blood sugar levels, and vitamin D and iron status. Sleep disorders, depression, anxiety, and medication side effects should also be evaluated.

"When fatigue persists, it is best to visit a medical facility as soon as possible for appropriate testing—not only to determine whether it is chronic fatigue syndrome but also for early detection of other underlying conditions," Kim emphasized.