A sunburn, while uncomfortable during the day, often becomes more painful once the sun goes down. This intensified discomfort has scientific reasons, rooted in the body’s natural physiological processes.
How Sunburn Causes Pain
Sunburn is the skin’s inflammatory response to damage from ultraviolet (UV) radiation, primarily from the sun. When skin cells, known as keratinocytes, absorb too much UV light, their DNA can be damaged. This cellular damage triggers the body’s immune system to initiate a protective and repair process.
This process involves the release of specific chemical messengers called inflammatory mediators. These include substances like prostaglandins and bradykinin, which sensitize nerve endings in the skin. The sensitization of these nerve endings leads to the characteristic pain, redness, and swelling associated with sunburn, as blood vessels in the affected area expand to increase blood flow for healing.
Why Pain Feels Worse After Dark
The heightened sensation of sunburn pain at night can be attributed to several interacting physiological and environmental factors. The body’s internal clock, or circadian rhythm, plays a significant role in how pain is perceived throughout a 24-hour cycle. Studies indicate that pain sensitivity tends to be highest in the middle of the night and lowest in the afternoon. This natural rhythm means that even without a sunburn, you might feel pain more acutely during nighttime hours.
Hormonal fluctuations further contribute to this nighttime discomfort. Cortisol, a hormone with anti-inflammatory properties, follows a circadian pattern, with levels decreasing at night. This nightly drop in cortisol reduces the body’s natural pain-suppressing mechanisms, making existing pain, like that from a sunburn, more pronounced. Melatonin, a hormone that rises at night to promote sleep, may have pro-inflammatory effects in the early phases of inflammation, potentially exacerbating the pain sensation.
Beyond biological rhythms, external factors amplify nighttime pain. With fewer daytime distractions, the mind becomes more focused on internal sensations, making pain more noticeable. The pressure from lying down on sensitive, inflamed skin can also cause irritation and discomfort.
Coping with Nighttime Sunburn Discomfort
Managing nighttime sunburn discomfort involves several practical steps:
Apply cool compresses or take a cool bath before bed.
Use soothing lotions, like aloe vera or calamine.
Take over-the-counter pain relievers, such as ibuprofen.
Wear loose, breathable clothing to minimize friction.
Elevate affected areas with pillows to reduce swelling.