Chest Pain; Dry mouth; Could not start hydrated; This spontaneous case was reported by a consumer and describes the occurrence of CHEST PAIN (Chest Pain) in a 56-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 008B21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.    On 25-Mar-2021 at 1:45 PM, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 25-Mar-2021, the patient experienced DRY MOUTH (Dry mouth). 25-Mar-2021, the patient experienced DEHYDRATION (Could not start hydrated). On 28-Mar-2021, the patient experienced CHEST PAIN (Chest Pain) (seriousness criterion hospitalization). The patient was hospitalized from 09-Apr-2021 to 10-Apr-2021 due to CHEST PAIN. On 10-Apr-2021, DRY MOUTH (Dry mouth) and DEHYDRATION (Could not start hydrated) had resolved. On 12-Apr-2021, CHEST PAIN (Chest Pain) had resolved with sequelae.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 09-Apr-2021, Blood pressure measurement: 192/99 (abnormal) 192/99. On 09-Apr-2021, Troponin: elevated (Inconclusive) elevated troponin levels.     The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.       Concomitant medications were not reported.  On 25Mar2021, the patient reported initial minor side effects of dry mouth while sitting in her car, but no other noteworthy side effects immediately following injection. Then, 2 or 3 days later the patient experienced chest pain that she reported started out as very mild, however, it grew in intensity over the following weeks, and she presented to the Emergency Room (ER) on Friday, 09Apr2021 per the caller's estimation.  Blood pressure taken at the ER was 192/99mmHg.  Full hospital work-up performed with the patient noted that she was negative for blood clots but had elevated troponin levels.  She said the hospital staff evaluated her heart's condition and found no sign of a heart attack.  On 10Apr2021, she was discharged with a new prescription of metoprolol. On the Monday after discharge, the patient had felt symptoms of chest pain again along with elevated blood pressure levels, so she returned to the ER where she was discharged without hospitalization and given a clonidine patch for any future blood pressure fluctuations.  Since then she had visited her Cardiologist and he has substituted her prescription metoprolol for amlodipine and losartan combination therapy, and to discontinue her prescription for clonidine patches.  Patient indicated her cardiologist is hopeful that her blood pressure should normalize over time and instructed patient not to receive her second dose of the vaccine. Additionally, patient reported that, from the time she received her vaccination, until she was discharged, she could not start hydrated.  She reported drinking large quantities of water, electrolyte replacement liquids, and Gatorade with no success.   Event of chest pain was resolved with Sequelae of elevated blood pressure.  Treatment included clonidine patches and metoprolol  On an unspecified date, the clonidine patches and metoprolol were stopped and amlodipine and losartan combination therapy was started.; 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.