difficulty thinking; Since the first dose, I have had pain between my chest and abdomen on my left side, behind and under the ribs/deep strong pain in chest and abdomen; Since the first dose, I have had pain between my chest and abdomen on my left side, behind and under the ribs/deep strong pain in chest and abdomen; Since the first dose, I have had pain between my chest and abdomen on my left side, behind and under the ribs; When I get that area too stressed (lower left chest, upper left abdomen area), I will feel the pain; dizzy/lightheaded; have difficulty thinking or processing thoughts; This is an ongoing bizarre issue; I noticed that if I avoid doing certain things, I can avoid the pain in chest, abdomen and dizziness.; disoriented; trouble in thinking; This is a spontaneous report received from a contactable reporter (Consumer or other non HCP) from medical information team. The reporter is the patient.  A 39-year-old male patient received BNT162b2 (BNT162B2), on 19Oct2021 as dose 1, single (Lot number: 30145BA) for covid-19 immunisation. The patient's relevant medical history and concomitant medications were not reported. The following information was reported: MENTAL IMPAIRMENT (medically significant), outcome "not recovered", described as "difficulty thinking"; CHEST PAIN (non-serious), ABDOMINAL PAIN (non-serious), outcome "not recovered" and all described as "Since the first dose, I have had pain between my chest and abdomen on my left side, behind and under the ribs/deep strong pain in chest and abdomen"; MUSCULOSKELETAL CHEST PAIN (non-serious), outcome "not recovered", described as "Since the first dose, I have had pain between my chest and abdomen on my left side, behind and under the ribs"; PAIN (non-serious), outcome "not recovered", described as "When I get that area too stressed (lower left chest, upper left abdomen area), I will feel the pain"; DIZZINESS (non-serious), outcome "not recovered", described as "dizzy/lightheaded"; THINKING ABNORMAL (non-serious), outcome "not recovered", described as "have difficulty thinking or processing thoughts"; ABNORMAL BEHAVIOUR (non-serious), outcome "not recovered", described as "This is an ongoing bizarre issue"; LOSS OF PERSONAL INDEPENDENCE IN DAILY ACTIVITIES (non-serious), outcome "not recovered", described as "I noticed that if I avoid doing certain things, I can avoid the pain in chest, abdomen and dizziness."; DISORIENTATION (non-serious), outcome "not recovered", described as "disoriented"; COGNITIVE DISORDER (non-serious), outcome "not recovered", described as "trouble in thinking".  Clinical course: Patient received the first dose of the Pfizer Covid 19 vaccine (unknown to caller if monovalent or bivalent) back on 19Oct2021 and issues started after the first dose. Since the first dose, patient had pain between his chest and abdomen on his left side, behind and under the ribs. The patient had side effects like deep strong pain in chest and abdomen, dizziness, trouble in thinking and disoriented. Patient's doctor is still trying to figure out and just wanted to narrow it down a bit. When patient gets that area too stressed (lower left chest, upper left abdomen area), patient would feel the pain building up in that area. Patient would get dizzy, lightheaded, have difficulty thinking or processing thoughts - all these typically associated with pain in chest and abdomen. This had happened a couple of times. It's pretty consistent, if the patient relaxes and not doing anything, patient typically don't feel anything. But once patient started to be getting active, ie: twisting, bending, trying to pick up heavy items, it may act up. Patient tried paddle boarding recently in Jul2023 to see how much he could handle, and the exertion of paddling would cause pain. Patient felt the pain and stopped before he got too dizzy. At first it was calm and easy and when patient turned around and faced the wind, he found out really quick that he couldn't continue since he started to feel the pain. Patient used to rock climb but have not done that. Patient noticed that if he avoids doing certain things, he can avoid the pain in chest, abdomen and dizziness. Like at the gym, he would try to do a little bit but if he pushes it too far, he would realize and remember that he need to stop. It was reported that this is an ongoing bizarre issue.; Sender's Comments: Linked Report(s) : US-PFIZER INC-202300283493 Same reporter, product, patient, different AEs, different dose;