My son has just returned to college via a 4-5 hour flight and his left lower leg from the knee down (including foot) has been numb with a pins-and-needles sensation but no pain or swelling or extra hotness in that leg versus the other. He is very flat footed but nothing like this has happened before. He did not get up at all during the flight and was not very hydrated. We are a bit concerned about whether he could have DVT (deep vein thrombosis). From reading various sources it seems that when symptoms are present (30-50%) it seems like there is invariably pain and swelling but not in his case - just numbness and pins and needles the last 36 hours. Any thoughts on liklihood this could be DVT?
Hello, This can be caused by mild nerve root compression at the level of the lower spine or due to electrolyte disturbances. Increasing electrolyte-rich fluid intake can help.  Hope I have answered your query. Let me know if I can assist you further. Take care Chat Doctor.