Hello and hope you are doing well.
As mentioned above, it could be due to Obstructive Sleep Apnea. When a person sleeps the airways are usually patent allowing normal passage for air entry. The upper airway that is at the region of the tongue and the soft palate is the most compliant (soft) part. So, this is liable to collapse and cause airway obstruction.
As the air way collapses the lungs do not have air entry leading to deoxygenation (decreased oxygen) of blood and the person wakes up. This period of non entry of air is called ‘Apnea’ and the waking up is called an ‘Arousal’. This keeps alternating and the person may not actually wake up all the time, but these repeated arousals can disturb the sleep architecture and cause fatigue, headaches and daytime sleepiness.
I would advise you to consult a sleep specialist who would assess with first a sleep questionnaire, and then he may ask for a polysomnogram, which is an overnight sleep study as this helps to detect the apneas. Treatment for Obstructive Sleep Apnea is by CPAP (Continuous Positive Airway Pressure) where air under gentle pressure is passed into the airways keeping it patent.
Hope this helped and do keep us posted.
sleep apnia ...ask the doctor if there is any meds or breathing exercises .