Most astronauts aboard ISS suffer from sinonasal congestion, study finds

For years, astronauts floating in orbit above Earth have reported headaches, stuffy noses and congestion. Now, new research shows these issues are far more than a minor nuisance during spaceflight — they’re prevalent among roughly 85% of astronauts aboard the International Space Station.

A collaborative study between Texas A&M University’s School of Engineering Medicine (EnMed) and Houston Methodist Hospital’s Department of Otolaryngology – Head and Neck Surgery is the first comprehensive look into how space travel affects sinonasal health. Drawing on nearly two decades of astronaut medical records in partnership with NASA’s Johnson Space Center, researchers found that out of 71 astronauts from 2000 to 2019, 60 reported having at least one sinonasal medical issue during their missions, and 75% of the ISS astronauts reported nasal congestion.

Texas A&M EnMed student Faizaan Khan, the first author of the study, said this is a common issue as astronauts adapt to microgravity. The fluid that normally pools in the legs on Earth shifts upward toward the head. That shift causes swelling and pressure in the sinuses — the hollow cavities in the face and skull that play an important role in respiratory health — resulting in headaches, congestion, fatigue and disrupted sleep, among other unpleasant symptoms.

These have been anecdotally reported by astronauts for decades, but Khan initiated the study to quantify the severity of the issue. The research was led by Dr. Masayoshi Takashima, chair of the Department of Otolaryngology – Head and Neck Surgery at Houston Methodist. Former astronaut David Hilmers from the Center for Space Medicine at Baylor College of Medicine also contributed. Co-authors include EnMed students Koyal Ansingkar, Roshan Dongre, Samuel Razmi and Isuru Somawardana.

“It really impacts their quality of life,” Khan said. Beyond discomfort, he said, there are serious health implications. When left unaddressed, sinonasal symptoms can lead to decreased sleep quality and fatigue, impaired decision-making and decreased productivity, the study notes.

 “When you’re sending people on one of mankind’s most expensive projects like the ISS to do vital research, every moment is precious,” Khan said. “We want to make sure they’re in good health and they don’t have things impacting their sleep or day-to-day living.”

Researchers also found that leaving the spacecraft for spacewalks or repairs presents its own issues. The change in pressure from inside the station to the inside of a space suit can lead to problems like dysfunction of the Eustachian tube, the structure connecting the ears to the throat.

Khan said the study’s findings are particularly relevant as space tourism becomes more common, making it important to understand how space affects even seemingly benign conditions like nasal congestion.

“In the future, it won’t always be the most healthy people going to space,” Khan said. “As we expand private space flight, we’ll have more regular citizens with health comorbidities, so it’s important to understand moving forward what the problems are that humanity will face as we’re traveling, exploring or conducting vital research.”

By Caitlin Clark, Texas A&M University Division of Marketing and Communications