seems after receiving 3 Pfizer Covid Vaccines I have now been diagnosed as Hyperthroid- or Subclinical Hyperthyroid; she couldn't hardly lift her arm and felt like she came down with something for a week.; tired and feels more tired than normal; felt like she was coming down with something/felt weird; heart pound; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP). The reporter is the patient.  A 56-year-old female patient received BNT162b2 (BNT162B2), on 11Apr2022 as dose 4 (booster), single (Lot number: FK9894) at the age of 56 years for covid-19 immunisation. The patient's relevant medical history included: "hypothyroid" (unspecified if ongoing); "Hashimoto's disease" (unspecified if ongoing). Concomitant medication(s) included: LEVOTHYROXINE taken for hyperthyroidism. Vaccination history included: BNT162b2 (DOSE 1, SINGLE; Expiry date: Jul2021), administration date: 06May2021, when the patient was 55-year-old, for COVID-19 Immunization; BNT162b2 (DOSE 2, SINGLE; Lot number: FW0172), administration date: 27May2021, when the patient was 55-year-old, for COVID-19 Immunization; BNT162b2 (DOSE 3 (BOOSTER), SINGLE; Lot number: FG3527), administration date: 29Nov2021, when the patient was 55-year-old, for COVID-19 Immunization, reaction(s): "seems after receiving 3 Pfizer Covid Vaccines I have now been diagnosed as Hyperthroid- or Subclinical Hyperthyroid"; BNT162b2 (DOSE 3 (BOOSTER), SINGLE; Lot number: FG3527), administration date: 29Nov2021, when the patient was 55-year-old, for COVID-19 immunisation, reaction(s): "My TSH is low", "TSI high". The following information was reported: FEELING ABNORMAL (non-serious) with onset 2022, outcome "unknown", described as "felt like she was coming down with something/felt weird"; PALPITATIONS (non-serious) with onset 2022, outcome "unknown", described as "heart pound "; MOVEMENT DISORDER (non-serious) with onset 2022, outcome "unknown", described as "she couldn't hardly lift her arm and felt like she came down with something for a week."; FATIGUE (non-serious) with onset 2022, outcome "unknown", described as "tired and feels more tired than normal"; HYPERTHYROIDISM (medically significant) with onset Sep2022, outcome "not recovered", described as "seems after receiving 3 Pfizer Covid Vaccines I have now been diagnosed as Hyperthroid- or Subclinical Hyperthyroid". Patient didn't feel much of anything for the previous 3 doses but her most recent dose she couldn't hardly lift her arm and felt like she came down with something for a week.  She was on levothyroxine, a low dose, and stopped taking it between the first blood test Jun2022 with a low TSH and her most current bloodwork Sept2022.  Had stopped her levothyroxine when her HCP had changed her to a different brand.  The different brand made her heart pound and she felt weird.  Decided not to take Levothyroxine anymore then TSH went down again Sep2022 after she stopped taking Levothyroxine. Diagnosed as hyperthyroid or subclinical hyperthyroid. Her HCP didn't say anything about it the first time her TSH went down.  Determined she was hyperthyroid from her last blood test Sep2022 when her TSI was tested and it looked like she was hyperthyroid.  Confirmed start date as Sep2022.  Outcome: Didn't feel any symptoms at all, subclinical hyperthyroid doesn't have any obvious symptoms. Didn't feel anything until her latest Pfizer COVID-19 shot. Didn't feel right, her arm was hurting really bad.  All the other vaccines she didn't feel anything. Latest Pfizer COVID-19 shot she had trouble lifting her arm and felt like she was coming down with something for an entire week.  Had a hard time shaking it off like she was fighting off something that never came. Her first blood test showed her TSH had gone down in Jun2022 and then her TSH went lower on her Sep2022 blood test. She'd stopped taking her levothyroxine between those two blood tests.  Levothyroxine is supposed to lower her TSH but she didn't take it in between June2022 and now.  Stopped Levothyroxine: Her HCP had changed her to a different brand and it made her heart pound and feel weird.  Felt fine on the one she had been taking all along.  When her HCP discovered her TSH went down her HCP wanted to lower the lose.  Was taking 25mcg and her HCP ordered another levothyroxine and only wanted her to take half the dose, only 12.5mcg.  She picked up her prescription, took one pill, and her heart was racing.  HCP wanted to lower her dose when the blood test results in Jun2022 said her TSH had gone down. The patient underwent the following laboratory tests and procedures: Blood thyroid stimulating hormone: (Jun2022) low; (Sep2022) low.