Felt upper neck getting sqeezing; Heart palpitation; Shortness of breath/Unable to breath/Shortness of breath while walking in normal pace or going upstairs; Side effects; Anxiousness getting worse/weakness of hands getting worse; Heaviness; Syncope; Feeling of cold/warm; Heart burn/Burning sensation upto throat; Dizziness; Position changed to standing from sitting; Passed out; No appetite; Heartburn; POTS(Postural orthostatic tachycardia syndrome); Autonomic nerve disorder; Fatigue; Unable to perform work; Feel tingling with both hands; Nervousness; Anxiousness; Weakness of upper arm/Leg weakness; Squeezing sensation of upper chest; Soreness of arm; Headache interferes with sleep/Inability to fall asleep; Pressure headache at nose and forehead/Severe headache; This spontaneous case was reported by a consumer and describes the occurrence of MUSCULOSKELETAL DISCOMFORT (Felt upper neck getting sqeezing), DYSPNOEA (Shortness of breath/Unable to breath/Shortness of breath while walking in normal pace or going upstairs), PALPITATIONS (Heart palpitation), LOSS OF CONSCIOUSNESS (Passed out) and SYNCOPE (Syncope) in a 53-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Penicillin allergy. Concomitant products included CALCIUM CARBONATE (CALTRATE [CALCIUM CARBONATE]) from 10-Jan-2020 to an unknown date for Calcium supplementation.    On 12-Jan-2021 at 11:00 AM, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 12-Jan-2021, the patient experienced PAIN IN EXTREMITY (Soreness of arm), INSOMNIA (Headache interferes with sleep/Inability to fall asleep) and HEADACHE (Pressure headache at nose and forehead/Severe headache). On 19-Jan-2021, the patient experienced DYSPNOEA (Shortness of breath/Unable to breath/Shortness of breath while walking in normal pace or going upstairs) (seriousness criterion hospitalization) and CHEST DISCOMFORT (Squeezing sensation of upper chest). On 21-Jan-2021, the patient experienced MUSCULAR WEAKNESS (Weakness of upper arm/Leg weakness) and ANXIETY (Anxiousness). On 22-Jan-2021, the patient experienced PARAESTHESIA (Feel tingling with both hands) and NERVOUSNESS (Nervousness). On 27-Jan-2021, the patient experienced IMPAIRED WORK ABILITY (Unable to perform work). On 10-Feb-2021, the patient experienced PALPITATIONS (Heart palpitation) (seriousness criterion hospitalization). On 13-Feb-2021, the patient experienced LOSS OF CONSCIOUSNESS (Passed out) (seriousness criterion medically significant), DIZZINESS (Dizziness) and SITTING DISABILITY (Position changed to standing from sitting). On 14-Feb-2021, the patient experienced MUSCULOSKELETAL DISCOMFORT (Felt upper neck getting sqeezing) (seriousness criterion hospitalization), FEELING OF BODY TEMPERATURE CHANGE (Feeling of cold/warm) and BURNING SENSATION (Heart burn/Burning sensation upto throat). In February 2021, the patient experienced DECREASED APPETITE (No appetite). February 2021, the patient experienced DYSPEPSIA (Heartburn), POSTURAL ORTHOSTATIC TACHYCARDIA SYNDROME (POTS(Postural orthostatic tachycardia syndrome)) and FATIGUE (Fatigue). February 2021, the patient experienced AUTONOMIC NERVOUS SYSTEM IMBALANCE (Autonomic nerve disorder). On 24-Feb-2021, the patient experienced SYNCOPE (Syncope) (seriousness criterion medically significant). On 26-Mar-2021, the patient experienced CHEST DISCOMFORT (Heaviness). On an unknown date, the patient experienced VACCINATION COMPLICATION (Side effects) and CONDITION AGGRAVATED (Anxiousness getting worse/weakness of hands getting worse). The patient was hospitalized from 14-Feb-2021 to 17-Feb-2021 due to DYSPNOEA, MUSCULOSKELETAL DISCOMFORT and PALPITATIONS. On 14-Jan-2021, PAIN IN EXTREMITY (Soreness of arm) had resolved. On 19-Jan-2021, DYSPNOEA (Shortness of breath/Unable to breath/Shortness of breath while walking in normal pace or going upstairs) had resolved. At the time of the report, MUSCULOSKELETAL DISCOMFORT (Felt upper neck getting sqeezing), LOSS OF CONSCIOUSNESS (Passed out), SYNCOPE (Syncope), INSOMNIA (Headache interferes with sleep/Inability to fall asleep), CHEST DISCOMFORT (Squeezing sensation of upper chest), DIZZINESS (Dizziness), FEELING OF BODY TEMPERATURE CHANGE (Feeling of cold/warm), DECREASED APPETITE (No appetite), DYSPEPSIA (Heartburn), POSTURAL ORTHOSTATIC TACHYCARDIA SYNDROME (POTS(Postural orthostatic tachycardia syndrome)), AUTONOMIC NERVOUS SYSTEM IMBALANCE (Autonomic nerve disorder), VACCINATION COMPLICATION (Side effects), SITTING DISABILITY (Position changed to standing from sitting), BURNING SENSATION (Heart burn/Burning sensation upto throat), CHEST DISCOMFORT (Heaviness), NERVOUSNESS (Nervousness), CONDITION AGGRAVATED (Anxiousness getting worse/weakness of hands getting worse) and FATIGUE (Fatigue) outcome was unknown and PALPITATIONS (Heart palpitation), MUSCULAR WEAKNESS (Weakness of upper arm/Leg weakness), PARAESTHESIA (Feel tingling with both hands), ANXIETY (Anxiousness), IMPAIRED WORK ABILITY (Unable to perform work) and HEADACHE (Pressure headache at nose and forehead/Severe headache) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 23-Jan-2021, Blood test: negative (Negative) Negative. On 23-Jan-2021, Computerised tomogram: negative (Negative) Negative. On 27-Jan-2021, Blood test: normal (normal) normal. On 13-Feb-2021, Electrocardiogram: normal (normal) normal. On 13-Feb-2021, Heart rate: 108 (High) Went up from 70s to 108.. On 13-Feb-2021, X-ray: normal (normal) normal. On 14-Feb-2021, Magnetic resonance imaging: postural orthostatic tachycardia syndrome. (normal) Diagnosis: Postural orthostatic tachycardia syndrome.. On 14-Feb-2021, Ultrasound scan: postural orthostatic tachycardia syndrome. (normal) Diagnosis: Postural orthostatic tachycardia syndrome.. On 24-Feb-2021, Electromyogram: autonomic nerve disorder and syncope. (Inconclusive) Autonomic nerve disorder and syncope.. On 24-Feb-2021, Quantitative sudomotor axon reflex test: autonomic nerve disorder and syncope (Inconclusive) Autonomic nerve disorder and syncope.. On 24-Feb-2021, Reflex test: autonomic nerve disorder and syncope. (Inconclusive) Autonomic nerve disorder and syncope.. On 28-Mar-2021, Laboratory test: ruled out heart attack (Inconclusive) Ruled out heart attack. On 28-Mar-2021, X-ray: ruled out heart attack. (normal) Ruled out heart attack..     The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.       Additional laboratory investigations included neurology study. Treatment for the event included acetaminophen, naproxen, lorazepam, metoprolol and fludrocortisone.  The patient consulted rheumatologist and no significant abnormal findings.  Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.   Most recent FOLLOW-UP information incorporated above includes: On 22-Apr-2021: Added reporter details, medical history, laboratory investigations, concomitant medication, new adverse events, seriousness of the events, outcome of events and treatment medication.; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.