began treatment to remove water from my system; suspected lung damage/something happened in my lungs; sleep difficult; This spontaneous case was reported by a physician (subsequently medically confirmed) and describes the occurrence of LUNG DISORDER (suspected lung damage/something happened in my lungs) and FLUID RETENTION (began treatment to remove water from my system) in a 90-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 011M20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included Smoker (hasn't smoked in 40 years) and Alcohol use (has not had in 30 years). Concurrent medical conditions included Hypertension since 03-Apr-1966. Concomitant products included METOPROLOL SUCCINATE (TOPROL) from 03-Apr-1966 to an unknown date and TRIAMINICIN [ACETYLSALICYLIC ACID;ALUMINIUM HYDROXIDE GEL, DRIED;CAFFEINE;MEPYRAMINE MALEATE;PARACETAMOL;PHENIRAMINE MALEATE;PHENYLPROPANOLAMINE HYDROCHLORIDE] from 03-Apr-1966 to an unknown date for Hypertension, OMEPRAZOLE (PRILOSEC [OMEPRAZOLE]) for an unknown indication.   On 17-Feb-2021 at 1:30 PM, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 15-Mar-2021 at 3:00 PM, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 15-Mar-2021, the patient experienced LUNG DISORDER (suspected lung damage/something happened in my lungs) (seriousness criterion hospitalization). On an unknown date, the patient experienced FLUID RETENTION (began treatment to remove water from my system) (seriousness criterion hospitalization) and INSOMNIA (sleep difficult). The patient was hospitalized from 18-Mar-2021 to 31-Mar-2021 due to FLUID RETENTION and LUNG DISORDER. At the time of the report, LUNG DISORDER (suspected lung damage/something happened in my lungs) had not resolved and FLUID RETENTION (began treatment to remove water from my system) and INSOMNIA (sleep difficult) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In March 2021, Laboratory test: normal no sign of a heart attack. In March 2021, X-ray: abnormal (abnormal) confirmed something was happening in lungs.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter considered LUNG DISORDER (suspected lung damage/something happened in my lungs), FLUID RETENTION (began treatment to remove water from my system) and INSOMNIA (sleep difficult) to be probably related.    The reporter is a physician and also the patient.  He stated that on the ight of the second vaccination, "being aware of the previous problem, I was conscious of similar things happening to my body."  On 16 Mar 2021 (reported as in the morning; also reported onset of event to be 17 Mar 2021), he went to his family doctor and was told to go to the emergency room (ER).  Instead, the patient went to a cardiologist, who ran tests and saw no sign of a heart attack.  The cardiologist suspected lung damage and sent the patient to urgent care, where x-rays confirmed "something happening in my lungs."  He was then admitted to the ER and later "began treatment to remove water from my system."  Cancer was ruled out.  The patient felt the events were most likely caused by mRNA-1273 and answered "no" when asked if there were other potential causes.   This case was linked to MOD-2021-016921 (Patient Link).