Research within the expanding field of space medicine has identified some ways during which a microgravity environment and other aspects can meddle with the human body during space missions.
A latest study has added to the sphere by showing that astronauts usually tend to experience headaches in space than previously known.
The study involved 24 astronauts from the U.S., European and Japanese space agencies who traveled aboard the International Space Station for as much as 26 weeks.
All but two of them reported experiencing headaches in space.
This was a bigger proportion than the researchers had expected based on prior anecdotal evidence.
The headaches – some resembling migraines and others resembling tension headaches – occurred not only throughout the first couple of weeks in space because the body goes through the means of adapting to microgravity, but in addition later.
The headaches occurring throughout the early period often present as migraine-like while those experienced later in space travel present more like a tension headache, the study found.
“We hypothesize that different mechanisms are involved for the early headache episodes – the primary one to 2 weeks in space – versus later headache episodes,” said neurologist WPJ van Oosterhout of Zaans Medical Center and the Leiden University Medical Center within the Netherlands, lead creator of the study published this week within the journal Neurology, opens latest tab.
“In the primary week, the body has to adapt to the dearth of gravity, generally known as space adaptation syndrome. This phenomenon is analogous to motion sickness, and could cause nausea, vomiting and dizziness, and headaches,” Van Oosterhout said. “The later headaches could result from a rise in intracranial pressure. As a result of microgravity, there’s more fluid accumulating within the upper a part of the body and head, leading to higher pressure within the skull.”
Migraines experienced on Earth are sometimes throbbing and pulsating headaches lasting 4 to seven hours, accompanied by symptoms equivalent to nausea, vomiting and hypersensitivity to light and sound, Van Oosterhout said.
Tension-type headaches on Earth are likely to be a more dull pain felt over your complete head without those other symptoms, Van Oosterhout added.
The astronauts – 23 men and one woman, with a mean age of about 47 – were aboard the International Space Station for missions that took place from November 2011 to June 2018, with a complete of 378 headaches reported by 22 of the 24 astronauts during a complete of three,596 days in orbit.
Not one of the 24 reported headaches within the three months after returning to Earth.
Thirteen of the astronauts were from NASA, six from the European Space Agency, two from Japan’s JAXA and one from the Canadian Space Agency.
None had ever been diagnosed with migraines prior to their space missions and none had a history of recurrent headaches.
Various documented effects of space travel include bone and muscle atrophy, changes within the brain, cardiovascular system and immune system, issues with the balance system within the inner ear and a syndrome involving the eyes.
Cancer risk from greater radiation exposure in space is one other concern.
Experts are unsure of how much of a barrier these effects may be on human space travel over prolonged periods, for example for journeys to our neighboring planet Mars or beyond.
“The honest answer is that we don’t know the results of long-duration space travel – possibly years – on the human body,” Van Oosterhout said. “It is evident that even short-term – days or even weeks – to medium-term – weeks or months – duration exposure to microgravity already has some effects, mostly reversible, on the human body. It is a clear task for the sphere of space medicine.”