Hashimoto's thyroiditis; States the bloating is not in her hips or waist, and is up to ribs.; has experienced weight gain/has gained 15 pounds; constipated; fluid retention; was just frustrated; this is awful and frustrating; TSH didn't go up; shut down my metabolism; bloating; Does not eat more than 500 calories a day or anything like that; TSH didn't go up; not being able to sleep; This is a spontaneous report from a contactable consumer or other non-health professional (patient reported for self). A 59-years-old female patient received BNT162B2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE, Solution for injection; Batch/Lot number: not reported), via an unspecified route of administration, on an unspecified date as (at the age of 59-years-old) dose 1, single and second dose via an unspecified route of administration on an unspecified date (Batch/Lot Number: not reported) as dose 2, single for COVID-19 immunisation. Medical history included blood pressure and underlying thyroid condition from an unspecified date and unknown if ongoing. The concomitant medications were not reported. Past drug history included levothyroxine (SYNTHROID) on an unspecified date for an unspecified indication (she could not tolerate). On an unspecified date, the patient experienced Hashimoto's thyroiditis, states the bloating is not in her hips or waist, and is up to ribs, has experienced weight gain/has gained 15 pounds, constipated, fluid retention, was just frustrated; this is awful and frustrating, TSH didn't go up, shut down my metabolism, bloating, does not eat more than 500 calories a day or anything like that and not being able to sleep. The reporter reported that, she experienced weight gain, she can't eat anything anymore, because every time she eats or drinks anything, she gains weight. Sometimes has a glass of wine to go to sleep at night, and that's like, 120 calories, then mentioned something else she ate yesterday. States repeatedly that most people don't care, and just buy bigger clothes, but this is "really annoying". States her weight does fluctuate, but this is extreme, and she cannot take it off. Reports that she has gained 15 pounds, and nothing is going to fit her this fall, knows others that have gained as well after receiving the Pfizer vaccine, one about 30 pounds, one about 10. She asked them both if they had underlying thyroid condition, and they said yes. She reports that she has Hashimoto's thyroiditis, and has high antibodies, thyroid was 2.3. This vaccine has completely shut down my metabolism and there's nothing else she can do. States tape measure went down because of exercise, but the scales continue to go up. She states that she wishes more people will report it, as well as that most of them are men. Says repeatedly that none of her clothes fit, but that it is "only 10Aug, so I have some time before fall". Caller reports that she had blood tests a month ago and they were normal (liver, pancreas, sonogram) and comprehensive aside from gynecologist. States the bloating was not in her hips or waist and is up to ribs. Has been exercising and eating better. Was ready to "just never eat again". Did not have exact dates of vaccinations, but said they were 2 months ago. Attempted to gather additional demographic and PCP information, but caller hung up before providing that. Mentions her doctor may increase her water pill. Tried Synthroid, but she could not tolerate that, because TSH was already normal, per patient report. The lab data included blood tests and sonogram they were normal (liver, pancreas, sonogram), thyroid was 2.3 with an unspecified unites, weight was gained 15 pounds and 112 pounds on an unspecified date. Outcome of the events was unknown.  No follow-up attempts are possible; information about lot/batch number cannot be obtained. No further information is expected.; Sender's Comments: Linked Report(s) : US-PFIZER INC-202101099308 same reporter/product, different patient / event.;US-PFIZER INC-202101099307 same reporter/product, different patient / event.