Sleeping while positioned upright, or in some instances, even standing, is not uncommon in the animal kingdom. Yet, for humans, finding comfort while sleeping in such positions—like during airplane trips or extended car journeys—is often challenging. This discomfort is partly because our muscles tend to relax and lose tone during specific sleep phases, as explained by the National Institute of Neurological Disorders and Stroke (NINDS).
In addition, prolonged sitting may raise the risk of deep vein thrombosis (DVT), a potentially dangerous condition, according to Medline Plus. For those who must sleep upright, precautions should be taken to mitigate the risk of DVT and to achieve quality sleep.
The Health Aspects of Upright Sleep
Sleeping in an upright position is neither inherently good nor bad. For some, due to health conditions like severe obesity or chronic obstructive pulmonary disease, it might even be the more comfortable option. Some individuals find relief sleeping in recliners, especially after surgeries. Dr. Jenny Iyo, a physical therapy expert and a member of the SleepFoundation.org medical review board, shared that post-operative shoulder patients often find solace in recliners as it prevents painful side rolling.
But, as Dr. Iyo emphasizes, this should be a temporary solution until one can sleep comfortably in bed. Always consult with a healthcare professional before making such postural changes.
Interestingly, some cultural groups have traditions of sleeping upright. A BBC feature highlighted a Buddhist retreat in Scotland where monks adopted this practice for several years. Nevertheless, due to our natural sleep cycle mechanics, many find upright sleeping challenging. Particularly during the rapid eye movement (REM) stage, our limbs tend to feel paralyzed to prevent dream enactments, making upright positions less comfortable.
Understanding Deep Vein Thrombosis (DVT)
DVT poses a risk, especially during long-haul flights. It's a condition where blood clots form in the thigh or lower leg veins after extended immobility. If these clots migrate to the lungs, it could result in a life-threatening pulmonary embolism. Factors like certain medications, smoking, and pregnancy might amplify the risk.
DVT symptoms include:
Tenderness or warmth over the clot region.
Clot-associated pain or swelling.
To counteract DVT risks, passengers on lengthy flights are advised to periodically stand and stretch. Staying hydrated is equally essential. Research from the National Library of Medicine, Biotech Information also suggests that reclining your seat to an angle greater than 40 degrees provides better sleep and might reduce DVT risk compared to a 20-degree angle. Yet, in some flights, frequent leg stretching might be the only viable solution.
Is Standing Sleep Possible?
Achieving sleep while standing is more complex for humans, given the muscle relaxation during REM sleep. In some rare circumstances, such as soldiers on guard duty, instances have been noted. In contrast, some animals like horses and flamingos have evolved mechanisms to sleep standing.
However, standing during sleep due to sleep disorders, such as sleepwalking, isn't a sign of healthy sleep but a manifestation of the disorder. It's always crucial to address such behaviors and ensure a safe sleep environment.