Carlos Yebra, cardiology resident: "When you get on a plane, your heart notices the drop in oxygen; that's why you notice palpitations."

Getting on a plane can not only cause you to lose your luggage, it can also alter the behavior of your heart. This is explained by Carlos Yebra, a cardiology resident, who has gone viral on social media with an informative video in which he issues a little-known warning: "When you get on a plane, your heart notices two things: a drop in blood pressure and a drop in oxygen levels. And your heart says, 'What's going on here?'"

Far from being an exaggeration, his words are supported by scientific evidence. Yebra explains that the body reacts to changes in atmospheric pressure and the reduction of oxygen in the cabin, something common on commercial flights operating at high altitudes, with ambient pressure set at around 2,400 meters. In this environment, the oxygen available in the blood decreases slightly, enough to generate physiological effects.

"To compensate for the lack of oxygen, your heart rate will increase, and that's why you may notice palpitations," he says. This is a normal response that occurs as a coping mechanism for the body, but it can be uncomfortable—or even dangerous—for some people with pre-existing conditions. "Be careful, because it can increase the risk of arrhythmias and heart attacks," he adds.

Medical studies confirm that airplane flights can have effects on the cardiovascular system. In a study published in Frontiers in Physiology , a group of 41 participants were exposed to a hypobaric chamber simulating the conditions of an airplane flying at an altitude of 2,100 meters. The result? Their heart rate increased by 3.9% and heart rate variability (HRV) decreased, indicating increased alertness of the sympathetic nervous system.

Furthermore, the British Civil Aviation Authority warns that certain patients with pre-existing conditions may experience reduced arterial oxygen saturation levels that trigger hypoxia. This condition can lead to mild tachycardia and increased oxygen demand from the heart, especially during critical phases of flight such as takeoff or landing.

If alcohol consumption is added to the effects of altitude, the risk increases. A study published in the medical journal Thorax analyzed volunteers who had drunk before undergoing a flight simulation at an altitude of approximately 2,400 meters. During sleep, these participants' oxygen saturation dropped to 85% and their heart rate rose above 87 beats per minute.

Researchers concluded that this combination significantly reduced sleep quality, prolonged hypoxemia (oxygen levels below 90%) , and generated considerable cardiovascular stress. Consequently, several experts and publications—such as Food & Wine and The Times—suggest avoiding alcohol before and during long plane journeys.

"It's not a serious issue for most healthy people," Yebra clarifies, but it can be significant for those who already have a heart condition. In fact, patients with coronary artery disease, arrhythmias, or respiratory problems are advised to consult their doctor before flying, especially on long-haul flights.