serious love serious lung serious man serious manner serious material serious matter serious matters serious measures serious medical serious medical condition serious medical conditions serious medical problem serious medical problems serious meeting serious men serious mental serious mental health serious mental illness serious mental illnesses serious mental problems serious message serious military serious misconduct serious misgivings serious mistake serious mistakes serious misunderstanding serious moment serious moments serious money serious mood serious moral serious motorcycle serious muscle serious music serious musician serious national serious nature serious need serious negative serious negligence serious neurological serious new serious news serious note serious obstacle serious obstacles serious offence serious offences serious offenders serious offense serious offenses serious offer serious offers serious omission serious one serious ones serious operation serious opposition serious or fatal serious or not serious or repeated serious outbreak serious pain serious part serious party serious penalties serious people serious person serious personal serious personal injury serious personality serious pest serious physical serious physical injury serious piece serious place serious plan serious planning serious plans serious play serious player serious players serious point serious policy serious political serious pollution serious possibility serious potential serious power serious pressure serious problem serious problems serious professional serious progress serious project serious proposal serious psychiatric serious psychological