Reply #11: Pulmonary embolisms... [View All]

...are blood clots, often starting in the legs, that break loose and flow into the heart or lungs. They can also go into the brain sometimes. They're caused by dehydration and lack of movement. It's also called "economy class" syndrome because people often get it after taking long flights on airlines, when they can't move around much.
I've actually been scared a couple of times when my legs felt kind of numb after flights.
The best way to make sure this doesn't happen is to drink plenty of water, don't drink alcohol, and, above all, get up and stretch your legs every hour or so. Especially if they start feeling like they're going numb. It also helps to take a blood thinner like aspirin before a flight.