If you've ever noticed your legs becoming numb or aching on a flight, it could be down to a number of reasons. Sitting for a long time in cramped spaces leads to reduced blood circulation, causing muscles to become stiff and achy.

Numbness and tingling in the legs after a flight (often called "paresthesia") is usually caused by prolonged immobility and restricted blood flow in a cramped economy seat. When you sit for hours, the edges of the seat can put pressure on the sciatic nerve or femoral cutaneous nerves, leading to that "pins and needles" sensation. More seriously, it can be a symptom of Deep Vein Thrombosis (DVT), where a blood clot forms in the deep veins of the leg. This risk increases on flights longer than 4 hours because the lack of muscle contraction prevents blood from pumping back to the heart. In 2026, medical professionals recommend "ankle pumps" every hour and wearing compression stockings to mitigate this. If the numbness is accompanied by swelling, warmth to the touch, or redness, it is considered a medical emergency, as a clot could potentially break off and travel to the lungs, causing a life-threatening pulmonary embolism.