Thank you for asking Healthcare majic. My name is Dr Ehsan Ullah & I have gone through your query. your 1st concern is know about the lowering of oxygen level during the severe asthma attack and 2nd concern is regarding tongue bit. regarding your 1 concern , the body s oxygen level falls drastically when there is either obstruction in the air way or reduced air entry to the lungs or reduced lung capacity to transfer oxygen from the lungs to the body parts where it s needed and in response to such situations , lips turn blue as a signal. turning of lips blue in patients with long lasting chest disease (chronic obstructive pulmonary diseases {COPD}) represents a condition called Chronic bronchitis in which air pressure in blood vessels (Partial pressure in arterial blood) is reduced and there is increase air residual volume with air trapping in the lungs. you need to continue with prescribed medications and do regular follow up. regarding your 2nd concern; biting tongue is although occurs in seizure attacks but in cases where you get unconscious , it can be because of accidental trauma to the tongue. if you have family history of seiures , or noticed such incident then you need to consult your physician . Hope this may help you. Let me know if anything not clear. Thanks.