The views expressed by me are for educational purposes only and do not establish a doctor patient relationship.
I am Mysticdoc, experienced Internal Medicine Specialist.
I am here to help you with your concerns.
Sleep apnea can cause these symptoms.
Sleep apnea is caused by the breathing problem during sleeping.
Oxygen level drops in the blood and causes these symptoms.
Obesity is one common cause of sleep apnea.
Also if you have any blockage in the nasal passage that can cause difficulty in breathing during sleep.
Diabetes, thyroid disorder are other possibilities which can cause these symptoms.
Sleep study should be considered to further investigate your problem.
Treatment is available for sleep apnea.
Please ask which part you did not understand.
but why does it happen only within the first 15 mins of sleeping and then it will never happen again during that night?
Don't think its the other thing you mentioned paroxysmal nocturnal dyspnea have no other symtoms; such as coughing, wheezing, etc. so the remedy then?