Explainer: Why astronauts experience headaches in space

NEW DELHI: Space travel, with its awe-inspiring vistas and weightless freedom, also brings forth a host of physiological challenges for astronauts. Among these, an unexpected and often underestimated issue is the prevalence of headaches during space missions. Let’s delve into the fascinating reasons behind this cosmic discomfort.
Research in the burgeoning field of space medicine has illuminated various ways in which microgravity and other space-related factors impact human physiology during space missions. Recent findings have further enriched this domain, revealing that astronauts are predisposed to experiencing more headaches in space than previously anticipated.
Study on headaches
In a notable study involving 24 astronauts from Nasa, the European Space Agency, and Japan’s JAXA, who served on the International Space Station for periods of up to 26 weeks, an overwhelming majority reported headaches. Surprisingly, aside from two astronauts, all participants experienced headaches, a higher rate than expected from earlier anecdotal reports. These headaches, varying from migraine-like to tension-type, were noted not only in the initial adaptation phase to microgravity but continued throughout the duration of their space journey.
Understanding the causes
According to neurologist WPJ van Oosterhout of Zaans Medical Center and Leiden University Medical Center in the Netherlands, and lead author of the study published in Neurology, the variation in headache types could be attributed to different underlying mechanisms. “In the first week, the body has to adapt to the lack of gravity, known as space adaptation syndrome. This phenomenon is similar to motion sickness,” he explained, linking it to the early onset of headaches. Conversely, headaches occurring later in the mission may stem from increased intracranial pressure due to fluid redistribution in microgravity.
Comparison with earth headaches
Van Oosterhout elaborated on the nature of migraines and tension-type headaches on Earth, contrasting them with those experienced in space. While migraines on Earth typically present with throbbing pain and other symptoms like nausea, tension-type headaches manifest as dull pain across the head without accompanying symptoms.
Astronaut demographics and reporting
The study spanned missions from November 2011 to June 2018, involving 23 male and one female astronaut, averaging around 47 years old. Across their time in orbit, 22 astronauts reported a total of 378 headaches over 3,596 days. Remarkably, none reported headaches in the three months following their return to Earth, underscoring the space-specific nature of these ailments.
Space travel and human health
The study sheds light on the broader spectrum of space travel effects on human health, including bone and muscle atrophy, cardiovascular and immune system changes, inner ear balance issues, and increased cancer risk due to heightened radiation exposure. The long-term implications of extended space missions, such as trips to Mars, remain uncertain, with Van Oosterhout emphasizing the nascent state of our understanding: “The honest answer is that we don’t know the effects of long-duration space travel on the human body.”
As humanity reaches for the stars, understanding and mitigating these health risks become paramount. The celestial frontier beckons, but it also demands that we unravel the mysteries of our own physiology. And so, amidst the vastness of space, astronauts navigate not only the cosmic expanse but also the subtle throbbing of celestial headaches.