That drops in her blood sugars occurred after the first; 1st shot I had some highs but not bad, then sever uncontrollable and unannounced lows that lasted days; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non HCP) from medical information team, Program ID: (005570). The reporter is the patient.  A 50-year-old female patient received BNT162b2 (BNT162B2), on 18Mar2021 as dose 1, single (Lot number: ER2613) at the age of 50 years, in left arm for covid-19 immunisation. The patient's relevant medical history included: "Type 1 diabetic" (unspecified if ongoing), notes: Type 1 diabetic; "Hypothyroidism" (unspecified if ongoing), notes: she was diagnosed with hypothyroidism 12-14 years ago; "Painful bladder syndrome" (unspecified if ongoing), notes: Painful bladder syndrome; "Fibromyalgia" (unspecified if ongoing). Concomitant medication(s) included: LEVOTHYROXINE taken for hypothyroidism. The following information was reported: BLOOD GLUCOSE INCREASED (non-serious) with onset 2021, outcome "not recovered", described as "1st shot I had some highs but not bad, then sever uncontrollable and unannounced lows that lasted days"; BLOOD GLUCOSE DECREASED (non-serious) with onset 2021, outcome "not recovered", described as "That drops in her blood sugars occurred after the first". Relevant laboratory tests and procedures are available in the appropriate section.  Additional information: Time the Vaccination Was Given: in the morning about 7-7:30am. Caller states her blood sugar the 1st day was kinda crazy up and down and the next day they started crashing on her overnight. Caller states she is not complaining. Caller states she is in her car waiting for her blood sugar to come up and can't concentrate well. Caller states she does not need emergent help right now. States she got all 4 Pfizer, 1 and 2 originally and then the booster shot and she just got another booster shot last Tuesday. Caller states it is the Pfizer Covid vaccine. States that her blood sugars won't go up since she got the vaccine. States that every time she gets it she has severe lows. Caller is wondering if more people have reported this or she might just be one of very few that has this. States that other people may be blowing it off because they are diabetic. States it's only after the vaccination that it happens. States she has hypothyroidism that started after the vaccine, just caught it like couple months ago. Her number was .084 and she takes a thyroid pill and that went from normal to severely low. States she takes Levothyroxine 87mcg once a day in the morning. Caller clarifies that she was diagnosed with hypothyroidism 12-14 years ago and they caught the severe low recently. States she was previously taking 112.75 or something and she has been taking levothyroxine for a couple of years. Caller states her blood sugar the 1st day was kinda crazy up and down and the next day they started crashing on her overnight. She has a Dexcom now thank God and you get them that often you don't wake up. States they started getting more severe and would spend a couple of hours drinking as much juice as she can and eating foods to stabilize her sugar and that works for half an hour to an hour. Caller relays she has already had 2 lows this morning and was up all night in the 50's and 60's and could not get them above 70 for a very long time. States she feels like she is ok now. States the night before she spent 2 hours at 40 and then was able to sleep for an hour and then it crashed down again. It was just all night long and she got maybe an hour and a half of sleep and that was it. States then it crashed again this morning. States it was 73 and had an arrow down meaning it was going down fast. Caller is asking if anyone else if having this, is she the only one. Prior Vaccinations (within 4 weeks): states she would have gotten the flu vaccine. AE(s) following prior vaccinations: States sore arm States she got the pneumonia shot before Covid hit and waited until later for the second. Caller does not recall the name of the Tetanus shot but she for sure did it in her other arm, right arm. Caller does not have NDC, lot or expiry to provide. Patient's Medical History (including any illness at time of vaccination) hypothyroidism, type 1 diabetes, painful bladder syndrome, fibromyalgia   No follow-up attempts are possible. No further information is expected.