Sir my age is 23 , sometimes when I walk and stop them sudden I feel my breathing frequently bloating fast in circular way and comes up to neck , I sudden feel nervousness , My ECG, ULTRASOUND, CHEST XRAY, CBC, LFT, RFT, THYROID, LIPID PROFILE, ELECTROLYTES TEST, ENDOSCOPY, HBsAG, HIV all test are normal and no addiction of Smoking or Alcohol, i consult with 4 pulmonologist they use stethoscope and say all are normal , please sir reply me what this actually is ,