Hi. The sudden ringing in the ears with head pressure during sleep points towards obstructed airway during sleep and may warrant an evaluation for obstructive sleep apnoea (OSA). However a single episode such as this does not mean that you have OSA but it definitely indicates a need for an ENT check up to rule out any abnormality within the nose, nasopharynx and laryngopharynx. It is possible that an allergic process or a deviated nasal septum or enlarged turbinates or adenoids or sinusitis could have precipitated the obstruction during sleep. These can be treated if identified. The ringing in the ear (tinnitus) can be explained by blockage of the eustachian tube (ET) which connects the back of the nose to the middle ear region. ET is important for equalizing the pressure between the ear and the atmospheric environment. During sleep enlarged turbinates can press on the opening of this tube or secretions can clog the tube and create blockage which creates a negative pressure within the ear and can irritate the inner ear leading to tinnitus. The head pressure can be because of the obstruction to airflow leading to reduced oxygen levels reaching the brain. The vessels around the brain dilate to increase oxygen supply and hence cause heaviness and headache. When that did not work the brain created a stimulus to wake you up from sleep and when you did your breathing recovered and symptoms disappeared. Do have this looked into by your ENT specialist. Typically for an OSA to be diagnosed you must have at least 30 such episodes every night followed by increased sleepiness during the day and gradual weight gain. From a single episode it cannot be concluded that this is the case. But the other causes can be picked and treated easily. If ENT causes are ruled out, then I would suggest a Neurology evaluation to check if something irritated your auditory nerve from within the brain and lead to tinnitus and the headache. As of now that doesn t seem very obvious.