seriousHer condition is not thought to be serious.
badHe got a bad case of food poisoning.
bigOnline fraud is a big problem.
majorIt's not a major problem, but it does need to be taken care of.
graveThe public are in grave danger.
severeHe suffered severe damage to his right ankle during the opening match of the season.
life-threateningHis injuries are not thought to be life-threatening.
urgentSuddenly, protecting the public from dangerous chemicals became an urgent matter.