In winter, even one cup of coffee can 'get on your nerves': why this happens

Many have noticed that the usual cup of coffee, which typically invigorates, can cause anxiety, heart palpitations, and increased excitement during the cold season. Experts explain that this is related not only to caffeine itself but also to seasonal changes in the functioning of the nervous system — lack of light, accumulated fatigue, and stress by the end of winter.

Caffeine blocks adenosine receptors — a substance that signals the brain about the need for rest. With normal sleep and sufficient light, this creates a mild invigorating effect. However, when the body experiences a lack of sleep and light, and the nervous system is under stress, the reaction to the same amount of caffeine can intensify — excitement, anxiety, and a feeling of inner turmoil increase.

Medical sources confirm that sensitivity to caffeine is quite individual and depends on genetics, metabolism, age, and even hormonal background. For some people, even small doses of the stimulant can cause side effects — from increased heart rate to insomnia and anxiety — if the body processes caffeine more slowly than usual.

Why this is especially noticeable in winter

Accumulated sleep deprivation. In winter, the short daylight hours and lack of sunlight affect circadian rhythms and sleep quality, which changes the perception of stimulants like caffeine.

Changes in neurotransmitter levels. Less light means less serotonin, which makes the nervous system more sensitive and less resilient to the stimulating effects of caffeine.

Chronic stress. By the end of winter, stress factors — work, household burdens, fatigue — accumulate, and caffeine amplifies the body's sympathetic 'fight or flight' response, which is felt as tension or anxiety.

Meanwhile, experts note that individual sensitivity to caffeine is not always a pathology — it is a normal physiological response that varies among individuals. If even small doses of caffeine lead to significant discomfort — strong anxiety, tachycardia, or insomnia — this may indicate heightened sensitivity due to genetics or metabolic characteristics.

Tips if coffee affects you too strongly

Reconsider the timing of consumption — for example, drinking coffee in the afternoon may exacerbate sleep disturbances.

Reduce the volume of the drink or choose caffeine-free alternatives — matcha tea, herbal infusions, chicory.
Pay attention to sleep quality — this can help reduce the overall sensitivity of the nervous system to stimulants.

...Increased sensitivity to coffee and caffeine by the end of winter is a combination of physiological features of the body and seasonal factors: accumulated sleep deprivation, lack of light, increased stress levels, and individual differences in metabolism. Understanding these mechanisms helps people consciously adjust their coffee consumption habits and take care of their well-being.