If monthly mortgage payments are not paid over a period of time, the mortgage company can foreclose. This means you will lose your property and may be evicted from your home.A foreclosure also becomes part of your credit report and may adversely affect one's ability to obtain credit in the future.
But one can avoid such a situation by taking action before the crisis happen.
You can see various tips to avoid forclosure at the link provided below.
http://www.freddiemac.com/corporate/buyown/english/owning/avoid_foreclosure.html#pay