Erm...Can you be more clear in your question? I presume you meant cause and effect on financial problems.
For causes, on the personal level, it may be due to a lack of financial education, as well as other education or skills required to take up a decent job, that can pay more than one's monetary NEEDS(things such as the cheapest food available that is not detrimental to health either in terms of quality or quantity, basic clothing etc, can't think of any other examples now). Also, one needs to be able to analyse choices of investments and purchase the right ones. It may also be due to health problems.
Some possible effects would be, on the personal level, one may live a sad life, in the sense that he does not have money for retirement or health problems etc. On the family level, if applicable, the children may need to starve, may not be able to get medical attention if necessary, or unable to attend college since scholarships are so hard to get. A divorce may happen or maybe even homicide followed by suicide by either parent. (In Singapore, there are a number of occurrences that a man disrupt public trains by jumping onto the tracks trying to escape the financial problems and family problems that arise as a result of the former.) On societal level, crime rates may increase, or dissent of the government may increase if a significant population lives in poverty and there is not much equity in the country. This may lead to riots or something. ( Such as the problems faced by tamils in early Sri Lanka? Not too sure, since I learned it a long time ago).
I hope my pointers do help