Hi I have a question about my dad. He s 73 years old. He just arrived home (to Kansas) from a visit to my house (in Colorado). Our house is at over 9000 feet in elevation, so it s quite an altitude change. He drove. He said that he feels fine, but it feels like the floor is vibrating. My mom is home with him, and she doesn t feel it. He doesn t feel sick and says he doesn t need to go to a doctor. I m just a little worries about him. Mom says it s just from sitting in the car all day. He s overweight and a Type 2 diabetic, but generally, with those two caveats, he s healthy for his age. All I m wondering is: does this sound like a big, red warning sign of something major? He s insistent that he s fine, but if I need to, I ll call him back and insist that he go to the doctor immediately.