If you are able to get a lower rate that what you currently have, you can save tens of thousands of dollars over the life of your loan. Also, most lenders don't charge as many fees to refinance a mortgage and depending on how much equity you have in your home you may be able to roll the closing costs into your new loan, still have a lower balance than your original loan, a lower rate, and a lower payment.
Refinacing your mortgage can allow you to take cash out of the equity which you have built in your home. You can pay off your higher interest debts and pay all of your debts at a lower interest rate. This will allow you to save money on a monthly basis and achieve your financial security.
Refinancing may not be that useful if you have already used up 90% or more of your home value in taking out a mortgage or any home equity loan. You won't be able to get the best rates available in the market as when you refinance a 90% LTV loan, you will probably require a loan of that value or higher. This will be quite closer to being a 100% financing option and hence mortgage refinance rates will be comparatively higher. Moreover, 100% loans are hardly available in times of mortgage market crisis.
Be Inquisitive. It's your responsibility to make sure that you understand the terms of your loan. Ask questions and listen carefully to the answers. Don't sign your loan documents until you are satisfied with the information and confident that you have made the right decision.