The term 'BIG PROBLEM' can be broken down into four crossword solutions: HEADACHE (8 letters), OBESITY (7 letters), SNAFU (5 letters), and CRISIS (6 letters). A HEADACHE is a common physical ailment that is usually caused by stress, tension, or illness. OBESITY is an excessive accumulation of body fat that can lead to serious health problems. SNAFU is a military acronym for 'Situation Normal, All Fouled Up, ' which is used to describe a chaotic or confusing situation. Finally, a CRISIS is an unstable and dangerous situation that requires immediate attention and action.