Dr. Toshi Is In! "We often hear doctors and other providers talk about blood clots. What exactly are they? Why are they so bad?"

Dear Dr. Toshi,

"We often hear doctors and other providers talk about blood clots. What exactly are they? Why are they so bad?"

Several years ago, on a flight to Japan, I heard the overhead announcement, "Is there a doctor or nurse on board? If so, please let one of the flight attendants know." I was ready to help! I immediately pushed the flight attendant's button and got out of my seat to find out what was going on.

Only a few years prior to that, as a fairly new family medicine resident in training, I was still afraid to fly--not because I don't like to fly, but because I was afraid to be called on a plane like this. I hadn't yet worked in emergency medicine alone at that point, and though I had practiced CPR on a medical mannequin, I hadn't had much real-life experience in emergency medicine, let alone all by myself! What if someone was having a heart attack? What if I had to do something like chest compressions to revive someone? What if someone was having a stroke? But when I actually encountered it that day, I felt confident and ready since I now had a few years of experience as a physician under my belt.

The patient was a Japanese middle-aged gentleman who had developed severe pain in one of his lower legs. He wasn't drinking any fluids because he wanted to avoid using the bathroom. He also hadn't left his seat for over 6-7 hours at that point. (By the way, did you know that the oxygen level in an airplane flying 33,000-42,000 feet is about the same as the level at elevations of 5000-9000 feet? Some people can actually get mild cases of High Altitude Sickness in planes!)

It was likely to be a DVT--a Deep Vein Thrombosis. That is, a blood clot, in this case, in the leg. (DVT can be in other parts of the body, too.) If this blood clot breaks loose and goes into the blood stream, it can go up and get stuck in the lungs, blocking blood flow through the lungs. This is called a pulmonary embolism (PE), and it can be fatal.

Fortunately, this gentleman wasn't having shortness of breath or chest pain, and his vital signs (blood pressure, temperature, heart rate, and respiratory rate) were normal, and his heart and lungs sounded normal. He was monitored through the rest of the trip (another 5-6 hours) and luckily, we flew the rest of the way without any more incidents. (You might be interested to know that most major airlines have physicians of their own on the ground who guide and help captains of airplanes make decisions whether to divert their flights if necessary. So, medical providers who happen to be on board flights aren't involved in the final decisions although they can make recommendations.)

Let's get back to blood clots. A blood clot is a thick mass of semi-hardened liquid, and blood clots in the body are exactly that: thick clumps of blood in the blood vessels. You might have seen something like that when you had a nosebleed, and thick blobs of gelatin-like blood came out when you blew your nose. Or you might have seen blood harden after a cut on the skin (scabs). We all have this mechanism to stop bleeding. But, when this happens in blood vessels, it can be life-threatening because it can go the lungs and become a pulmonary embolism.

Even though you may not be flying anywhere in the near future especially because of COVID-19, you might be planning to take a trip in your car or camper. So, I wanted to cover this subject for you today because one of the risk factors for getting blood clots is long-distance travel, whether in a plane or vehicle.

First, make sure you stay well-hydrated by drinking plenty of fluids on your trip. (I've seen really thick blood that was as thick as ketchup before!) Second, stop every two hours or so and walk around 5-10 minutes to get your blood flowing and prevent it from pooling in your legs.

By the way, this also applies to people who can't leave home due to COVID-19. Even sitting in a chair for many hours at a time can cause a blood clot. And don't let yourself get dehydrated.

Dr. Toshiko (Toshi) Luckow, MD is a Family Medicine physician at the West River Health Services hospital and clinics.