National mortgage rates rose for a second straight week, hitting a key level that may cut into home loan demand.

Interest rates on 30-year fixed-rate mortgages averaged 5.00 percent for the week ending Oct. 22, up from the previous week’s 4.92 percent, according to a survey released Thursday by home funding company Freddie Mac

Many industry experts view 5 percent as a key psychological level. When rates drop below it, home loan demand tends to rise, while the opposite holds true when rates rise.

Still, mortgage rates remain low. A year ago, 30-year mortgage rates averaged 6.04 percent. The rate is significantly higher than the record low of 4.78 percent set in the week ended April 2.

"Following bond yields, long-term mortgages rates edged up slightly this week,” Frank Nothaft, Freddie Mac vice president and chief economist, said in a statement.

Mortgage rates are linked to both Treasury and MBS yields. Freddie Mac started the survey in 1971.