Why cold months make you feel exhausted even after extra sleep

Winter fatigue often leaves people sleeping an extra hour and still feeling exhausted by mid-morning. Dr Niranjan Singh, additional director of internal medicine at CK Birla Hospitals in Jaipur, points out that the human body clock relies on light to manage its twenty-four-hour cycle. Shorter days and staying indoors keep melatonin, the hormone that causes drowsiness, elevated longer than normal. This causes daytime sleepiness and low energy, while reduced sunlight also pulls down overall mood and alertness.

Lifestyle Factors

Colder weather discourages physical activity, making outdoor walks or indoor workouts unappealing. This drop in movement leads to increased physical sluggishness. Diet changes during winter also play a part, as people tend to choose heavier foods and often neglect proper water intake.

Medical Causes

Persistent tiredness is not always seasonal. Conditions like anaemia, thyroid problems, vitamin B12 or vitamin D deficiencies, diabetes, and untreated sleep disorders frequently trigger constant fatigue. Additionally, severe low energy and mood shifts during dark months can indicate seasonal affective disorder.

Context

Seasonal tiredness and sleep changes are common physiological responses to altered light exposure and temperature drops during winter months. Maintaining consistent daily routines and proper medical screening helps distinguish ordinary seasonal sluggishness from underlying health conditions.