Gloria Brown didn’t get a good night’s sleep. Her husband, Arthur Brown, 79, has Alzheimer’s disease and had spent most of the night pacing their bedroom, opening and closing drawers, and putting on and taking off his jacket.

So Ms. Brown, 73, asked a friend to take her husband out for a few hours one recent afternoon so she could grab a much-needed nap. She was lucky that day because she didn’t need to call upon the home health aide who comes to their house twice a week.

Paying for help isn’t cheap: The going rate in the San Francisco Bay Area, where the Browns live, ranges from $25 to $35 an hour. Ms. Brown estimates she has spent roughly $72,000 on caregivers, medications and supplies since her husband was given his diagnosis four years ago.

“The cost can be staggering,” said Jim Patterson, a Republican state assemblyman from Fresno who is the author of a bill that would give family caregivers in California a tax credit of up to $5,000 annually to help offset their expenses.