When suffering from a cold, blocked nose, fever, headache, or cough, symptoms often worsen at night. Why does this happen? Each person’s brain has a 24-hour clock known as the Circadian Rhythm, which regulates our alertness and sleep cycles according to changes in environmental light.
Our physiology and behaviors are shaped by the Earth’s rotation, such as the change between day and night. The brain receives signals to prepare for sleep as the sun sets. Alongside this, the Circadian Rhythm activates immune cells, making them more active. These cells become more active every night in different parts of the body, leading to bacterial or viral attacks in sensitive areas, causing inflammation and irritation.
