This is why fingernails detach from fingers of astronauts after a walk in space

The challenges posed to the human body during space travel are numerous, and one intriguing phenomenon experienced by astronauts is onycholysis, the apparent detachment of fingernails following extravehicular activities (EVAs) in space.

Space conditions, distinct from Earth’s familiar environment, bring about various physiological challenges, and onycholysis has emerged as an unexpected consequence of space exploration.

This condition, onycholysis, has proven to be a complex issue with connections to atmospheric pressure and spacesuit design.

The minimal ambient pressure in space necessitates pressurizing astronauts’ spacesuits for safety during EVAs.

However, this presents a challenge for hands, resulting in common injuries and onycholysis. The pressurized gloves, crucial for survival, limit movement, causing pain, muscle fatigue, and even severe injuries, as reported by Science Alert.

Persistent glove-related injuries have been observed, with studies indicating that hand injuries, including onycholysis, continue to occur during EVAs despite advancements in spacesuit design.

In a 2010 study that examined 232 reported hand injuries in astronauts, a correlation was identified between knuckle width and the risk of injury.

The study proposed that the design of spacesuit gloves, particularly their impact on knuckle mobility, plays a critical role in hand injuries, including onycholysis.

Spacesuit gloves, intricate and composed of multiple layers, are designed for comfort, pressure regulation, movement, and protection from space hazards.

Despite these complexities, finding a glove design that minimizes the risk of onycholysis has proven challenging.

Engineer Christopher Reid led a study examining 31 reported onycholysis injuries among astronauts, offering new insights. The research highlighted glove design as a significant factor, with one type associated with an 8.5 times higher risk of fingernail loss. Middle finger injuries, influenced by glove sizing and length, were prevalent, and onycholysis appeared more likely in women than men.

While the study suggests that poor glove fit may contribute to onycholysis, future developments in Artemis-era spacesuits hold promise. These advancements aim to address issues related to glove design and fit, potentially minimizing the risk of onycholysis among astronauts.