You likely feel sicker at night because your immune system becomes more active when your cortisol levels naturally decrease.
Here's a breakdown of why you might experience worsened symptoms in the evening:
The Role of Cortisol
Cortisol, a hormone closely linked to immune system function, typically follows a daily cycle.
- Higher Levels During the Day: Cortisol levels are generally higher during the daytime. This higher cortisol acts as an immunosuppressant, meaning it suppresses the activity of your immune system to some extent.
- Lower Levels at Night: As evening approaches and you prepare for sleep, cortisol levels naturally decline.
The Immune System's Night Shift
With lower cortisol levels at night, your immune system is freed up to be more active.
- Increased Immune Activity: This increased activity means your body is working harder to fight off any illness or infection.
- Exaggerated Symptoms: This increased immune activity often manifests as more pronounced symptoms, such as:
- Fever Spikes: Inflammation, a key part of the immune response, increases, leading to a higher body temperature.
- Increased Congestion: Your body produces more mucus as it tries to trap and expel pathogens.
- General Discomfort: The overall inflammatory response can make you feel achier and more fatigued.
Other Contributing Factors
While cortisol plays a significant role, other factors can contribute to the perception of feeling sicker at night:
- Lack of Distraction: During the day, activities and social interactions can distract you from your symptoms. At night, without these distractions, you may focus more on how you feel.
- Positioning: Lying down can worsen congestion and coughing, making you feel more uncomfortable.
- Dehydration: You may not be drinking as much water in the evening, leading to dehydration, which can exacerbate symptoms like headache and fatigue.
In summary, the interplay between your body's natural cortisol cycle and your immune system's response is the primary reason why you might feel sicker at night. The absence of daytime distractions and changes in body positioning can also contribute to this perception.
