i periodically get what i can only describe as a bubbling sensation in my head - like multiple waves of passing dizziness but "bubbly" because it starts more severe then tapers off. the time it takes to taper off varies. seems to coincide with stress or pms/migraines. it also sometimes happens in my chest simultaneously. overwhelming tiredness often accompanies it. my bp has always been measured normal, cholesterol healthy, get annual physicals all healthy. i could exercise more as i am early 40's, female, 5'10", 180#. Any thoughts on what this is or what to have checked.