Start with hard-to-reach shelves or cabinets placed too far up on the wall. If you can make the items in those cabinets easier to access, you'll reduce the number of times your parent must stand on a stool or chair. If there's no way to eliminate the high storage space, at least move most-used items to the lower shelves and make sure a sturdy stepladder is on hand. Many small stepladders are designed with extra-wide treads and easy-to-grab supports, and some fold down easily to fit in small closets.
Next, take a look at where the microwave oven is placed. The people who use it should never have to reach above eye level to take out food -- a good policy for any kitchen, but an absolute necessity for those whose hands may not be as steady as they used to be.
If the microwave is built into a base cabinet below the counter, you may want to move it up to sit on the countertop. Even though a low-placed microwave doesn't pose a serious safety risk, it does require you to bend over to use it.
The dishwasher also requires a lot of bending; if possible, try installing the appliance on a 6- to 8-inch platform to reduce the reach when loading and unloading. This trick also works in the laundry room to raise the clothes dryer to a more comfortable height.
Swap hard-to-grip small knobs for C-shaped or D-shaped cabinet door and drawer pulls. This type of pull is a plus for any kitchen and can help take the pain out of cooking for someone with arthritis.
Apply the same logic to the kitchen sink, and put in a lever handle instead of knobs that require twisting.
While you're at it, think about switching doorknobs throughout the house to lever latches -- they're easier to use and look good too.
To make bathing easier and more comfortable, put a small, nonslip seat in your parents' bathtub or add a permanent seat to the shower. You can buy easy-installation products for most showers, or you can build in a seat as part of a remodeling project. Combine the seat with a versatile handheld showerhead. These showerheads are inexpensive, easy to install, and readily available at most hardware stores and home centers.
Falling on wet and slippery bathroom floors is probably the most serious bathroom safety concern. To reduce the risk, add water-absorbent rugs with rubberized nonskid bottoms. Rubber mats and slip-resistant appliques can prevent falls in the shower.
If slip-and-fall accidents are a major concern, be sure to install grab bars near the shower and toilet. Select bars that are hefty enough to support a person's weight, and be sure to anchor the bars into wall studs for maximum stability.
Many older adults find it more convenient to live on a single level, entirely avoiding the need to use stairs. If your parents still live on multiple levels, check the stairway railings regularly. With daily use, railings can become wobbly. When you visit, give the railing a little tug to see whether the screws or anchor bolts need tightening.
Also, check to see whether the railing is the right height for comfortable use. Most railing heights are standard, but your parents may not be of average size. If the railing is primarily being used by someone who is particularly tall or short, adjust the railing's position so it's comfortable to use.
Inadequate lighting in stairwells is another common flaw that can be easily remedied. If the stairwell seems dark, first try cleaning the light fixtures. Another easy solution is to switch to higher-wattage bulbs. A more complicated method is to install an additional overhead fixture or a wall sconce. If, on the other hand, you just need to brighten a hallway or stairwell, a night-light can often put a little glow in the right place.
Be sure your parents' home has smoke alarms, and remember to check them twice a year to ensure that they work. Some smoke alarms will beep periodically when the batteries are low; to avoid this, replace the batteries each year (even if the alarm doesn't seem to need new ones yet). This way, you'll prevent the alarms from beeping and prevent your parents from trying to climb up on a chair or stepladder to tend to the alarms.
Also install a carbon monoxide detector that will sound if the level of carbon monoxide rises to unsafe levels. Follow the manufacturer's instructions and mount these alarms near gas-burning appliances. Test the alarm with a parent present, so she or he can hear the difference between the carbon monoxide detector and the fire alarm.