weakness; nausea/her stomach is kind of queasy; She spent 2 days in bed, unable to get out to do anything other than pee, get something to eat and go back to bed; brain fog; she can't concentrate, it is affecting her head; dizziness/dizzy; exhausted/tiredness/tired; faint episode; achy arm; abdominal pain; her sugars really shot up in couple of hours, went to 220s; shivers, cold.; shivers, cold.; The initial safety information received was reporting only non-serious adverse drug reaction(s), Upon receipt of follow-up information on [22Mar2021], this case now contains serious adverse reaction(s). Information processed together.  This is a spontaneous report from a contactable consumer (patient). A 52-year-old female patient received the first dose of bnt162b2 (PFIZER BIONTECH COVID-19, Lot number and expiry date were not reported), via an unspecified route of administration, administered in left arm on 18Mar2021 (at the age of 52-year-old) at single dose for COVID-19 immunization. Medical history included Diabetes, ongoing PoTS diagnosed around Dec2020 or Jan2021, MTHFR (methylenetetrahydrofolate reductase genetic mutation) genetic mutation, Genetic/Chromosomal abnormalities and lost some weight. The patient had prediabetes for long time, in last year gotten little bit bad; back under control sugars running 125-130. That's not why she is feeling like this. Measures her sugar 3 times daily keeps Diabetes diet controlled mostly. With regards to her MTHFR: methylenetetrahydrofolate reductase genetic mutation. This genetic mutation makes her not methylate well, they told her she is a poor meythelator. Family history included diabetes and high blood pressure. Her dad passed away from either Diabetes or Lung cancer; she is not sure which-he had lung cancer but afterwards when patient talked to her sister, sister mentioned dad's diabetes got really bad after the chemo and everything; but that is neither here nor there in the end; it could have been from Diabetes or lung cancer. He was a smoker for his entire life, even though chemo he could not quit the cigarettes, could not give it up even on his death bed. Concomitant medications included ergocalciferol (VIT D), cyanocobalamin (VIT B12), and ongoing ascorbic acid (VITAMIN C); all were taken for vitamin supplementation. The patient previously received varicella zoster vaccine rge (cho) (SHINGRIX) on 19Feb2021 for immunization and experienced achy arm and tired for a day. About 15 years ago when having her daughter, the patient had severe reaction to Magnesium sulfate for preeclampsia. They gave her Magnesium sulfate twice which made her comatose twice, she does not know why they gave it to her the second time. She also had a reaction to calcium levomefolate (DEPLIN), like a methylfolate thing. She reported she was on Glimepiride for Diabetes previously which was stopped a couple of weeks ago because she was having a lot of blood sugars that did not sit well with her. This consumer is the patient who called regarding symptoms she experienced following first dose of Pfizer-BioNTech COVID-19 Vaccine administration on 18Mar2021. The first symptoms she had were an achy arm later on that day of 18Mar2021. On 19Mar2021, the next morning she woke up totally exhausted. She spent 2 days in bed, unable to get out to do anything other than pee, get something to eat and go back to bed. Some of the symptoms lifted yesterday, 21Mar2021 during the day. She kind of got up, was still kind of tired but pushed through it thinking she couldn't just sit in bed. She spent a little time outside while her daughter was at the pool; she was sitting in a chair away from other people. When she came home she was really tired and dizzy on 21Mar2021 and decided to go to bed. The patient also experienced weakness and nausea on unspecified date. After the Pfizer BioNTech COVID-19 Vaccine injection/shot on Thursday, 18Mar2021 she had a faint episode. They thought the faint episode was probably from anxiety, reason unknown; but she had a lot of faint episodes before she went to bed. She woke up 1-2 hours later on 18Mar2021 with really bad abdominal pain all night, shivers, cold. When she got up in the morning she was really tired; she had to take her daughter to school and barely drove to school half-way coherent because her daughter was talking to her. She was not doing great, she came back home, she is still tired, has been on the couch all day; her stomach is kind of queasy, not good. This is day 4 so she is concerned a little bit. She is too tired to go downstairs during this call; this thing is kicking her butt; she is having a brain fog with this thing, she can't concentrate, it is affecting her head. She has other medical condition Diabetes: After she got the Pfizer-BioNTech COVID-19 Vaccine her sugars really shot up in couple of hours, went to 220s on 18Mar2021; sugars back down the next day (19Mar2021). She is terrified of what is going to happen after the second dose of Pfizer-BioNTech COVID-19 Vaccine. She verified she has not had any visit to physician's office, emergency room or hospitalization related to these events; not yet, but she is considering whether to go or not.  The outcome of the event exhausted/tiredness/tired was not recovered, and the outcome of the remaining events was unknown.  Information about the Lot/batch number has been requested.