With her first booster shot, had mild lightheadedness.; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP). The reporter is the patient.  An 82-year-old female patient received BNT162b2 (BNT162B2), on 14Dec2021 as dose 3 (booster), single (Lot number: FD7218) at the age of 82 years, in left arm for covid-19 immunisation. The patient's relevant medical history included: "cholesterol" (ongoing), notes: cholesterol problems Diagnosed years ago; "High blood pressure" (ongoing), notes: high blood pressure Diagnosed years ago. Was told her blood pressure was very good.; "COVID" (unspecified if ongoing), notes: a very mild case of it. Confirmed this was prior to caller receiving any of her COVID-19 Vaccines.; "ton of allergies" (unspecified if ongoing), notes: States she has a ton of allergies.; "urinary tract infection" (unspecified if ongoing), notes: Had a urinary tract infection about a month ago. The patient's concomitant medications were not reported. Vaccination history included: BNT162b2 (COVID-19 Vaccine: Dose 1, Single, Manufacturer: Pfizer, Date: 25Feb2021, LOT: EN6202, Left arm), administration date: 25Feb2021, when the patient was 81-year-old, for COVID-19 immunization; BNT162b2 (COVID-19 Vaccine: Dose 2, Single, Manufacturer: Pfizer, Date: 18Mar2021, LOT: EN6204, Left arm), administration date: 18Mar2021, when the patient was 81-year-old, for COVID-19 immunization; Pneumonia shot (pneumonia shot), administration date: 2022, for Immunisation. The following information was reported: DIZZINESS (non-serious) with onset 14Dec2021, outcome "recovered", described as "With her first booster shot, had mild lightheadedness.". The action taken for BNT162b2 was unknown.  Additional information: She was at hospital receiving the vaccine, stayed there for a while and then went home. Was at the hospital for an hour when everyone else left after 20-25min. It stopped on the same day. She is calling about her second booster shot: She was there at the hospital and was lightheaded She stayed for a while, it seemed to be getting better She went home Her arm where she got the booster shot was her left arm, was extremely painful. When she went to sleep, couldn't sleep on left side Couldn't press anything on that left arm Had tiredness, headache, muscle pain, muscle pain in the left arm, left arm was splotchy red, had joint pain.  Something seemed wrong with muscles and joints. She lives in assisted living. When she came back was told she had a slight fever, she took Tylenol, stating this was in morning. In the afternoon, she took another Tylenol, and the slight fever went away. Then something happened that night. Went to sleep, in middle of night, her eyes opened, and she was shaking all over. Her arms instead of being flat on bed, from the elbows to fingertips were elevated and shaking badly. Whole body was shaking. She was scared and terrified. This was not a side effect on the chart. Didn't know what was happening. Thought she was dying. She blanked out. She didn't know anything until 6am the following morning and couldn't believe she was alive. Spent the rest of the day in bed, didn't want to move Was so scared of what was going on. The patient received treatment for Tylenol for slight fever, no other treatment was received. After this experience, hopes she doesn't have to get a third booster.  No follow-up attempts are needed. No further information is expected.