Cardiologist explains what really happens to your body on a flight and how to protect yourself

Flying can be tough on your body. But these small habits can make a big difference. Your heart's working hard up there – here's how to help it out.

While most passengers view a flight as a simple transition between two points, your internal organs are actually running a marathon in the sky. Dr Dmitry Yaranov, a US-based cardiologist specialising in heart failure and transplantation, took to Instagram to pull back the curtain on the 'cardiology version' of air travel.

Cardiologist Dr Dmitry Yaranov shares what happens to your body on a flight. (Freepik)

The invisible stress test

In a post shared on March 14, he warned that the fatigue we often mistake for simple jet lag is actually a complex physiological reaction to a high-altitude environment. According to Dr Yaranov, the body undergoes several immediate shifts the moment the cabin is pressurised. "Most people think flying is just sitting in a chair in the sky. But your body is doing real work up there," he explained.

He highlighted that by shifting the focus from mere comfort to physiological protection, travellers can arrive at their destinations feeling refreshed rather than depleted. The cardiologist highlighted several key changes that occur during a typical flight:

⦿ Oxygen deprivation: as cabin pressure drops, oxygen levels in the blood fall.

⦿ Cardiac strain: the heart must pump harder and faster to deliver the same amount of oxygen to your tissues.

⦿ Thicker blood: because cabin air is drier than most deserts, you lose significant water through respiration. This causes blood volume to drop, making the blood more viscous.

⦿ Circulatory sluggishness: prolonged sitting causes blood to pool in the lower extremities, leading to heavy, swollen legs.

⦿ Weakened immunity: the dry air parches the lining of the airways, stripping away the first line of defense against airborne viruses.

To combat these effects, Dr Yaranov shared his personal protocol for maintaining heart health and immune integrity while travelling.

1. Pre-game your hydration

Don't wait for the beverage cart. Dr Yaranov suggested hydrating well before boarding to ensure you start the journey 'ahead, not behind'.

2. Avoid the 'thickening' duo

He advised avoiding salt and alcohol strictly while in the air. Both substances contribute to dehydration and further thicken the blood, increasing the workload on the heart.

3. Keep the 'pump' primed

To prevent blood pooling and potential clots, the doctor recommended standing or stretching every single hour. After landing, he suggested a brisk walk to 'reset' blood flow and oxygen delivery.

4. Support your barrier

Using a saline nasal spray before takeoff can keep the airway lining moist, helping the immune system stay functional despite the arid cabin environment.

"Tiny habits. Massive difference when you land," Dr Yaranov concluded, adding, "Your heart travels with you. Treat it like it matters."

Note to readers: This report is based on user-generated content from social media. HT.com has not independently verified the claims and does not endorse them.

This article is for informational purposes only and not a substitute for professional medical advice.