A second mortgage, also called a home equity loan, often has a much higher interest rate than a first mortgage. This is because the second mortgage isn’t repaid until the first mortgage is repaid if you default. The additional interest is a form of protection for your secondary lender.
If you’ve accrued additional equity, you may be able to refinance the second mortgage to a lower rate or save even more by combining both your first and second mortgage into a new first mortgage. Not only will your payments be simplified, but also your new interest rate will most likely be lower than the average interest rate of your two loans. This could potentially save you thousands of dollars in interest over the life of the loan.