What Causes Persistent Drowsiness and Lack of Energy?

In daily life, there is always a group of people who frequently feel drowsy, as though they haven’t had enough sleep—groggy during the day and unable to fall asleep at night. Persistent drowsiness not only harms physical health but also causes numerous practical difficulties in everyday life. So, what are the underlying causes of chronic fatigue and low energy? Below, we address this question.

What Causes Chronic Fatigue and Low Energy?

1. Physiological Factors

Staying up late regularly and poor sleep quality are common physiological causes of daytime drowsiness. Additionally, postprandial blood glucose elevation stimulates the brain to produce substances that induce sleepiness. Prolonged sedentary work can impair circulation, thereby affecting sleep quality. However, these are all reversible physiological factors.

2. Environmental Factors

Seasonal transitions often trigger drowsiness—for instance, “spring fatigue,” “autumn lethargy,” or even “winter hibernation.” Such phenomena result from environmental influences; the human body must adapt physiologically to changing external conditions. Similarly, poor indoor air circulation can readily induce drowsiness.

3. Pathological Factors

Numerous medical conditions can cause excessive drowsiness. For example, individuals with depression often exhibit reduced motivation for social interaction and may experience persistent fatigue and prolonged sleep duration—both entirely consistent with the disorder’s clinical presentation. In diabetes, elevated blood glucose levels act as a physiological trigger for drowsiness, operating via mechanisms similar to those underlying postprandial sleepiness.

The above outlines the primary causes of chronic fatigue and low energy. We hope this information proves helpful to you.