We all forget things once in a while. Maybe you've forgotten to send a card for someone's birthday or to return an overdue library book.

Forgetting stuff is a part of life and it often becomes more common as people age.

What Is Alzheimer's Disease?

Alzheimer (say: ALTS-hy-merz, ALS-hy-mer, or OLS-hy-merz) disease, which affects some older people, is different from everyday forgetting. It is a condition that permanently affects the brain. Over time, the disease makes it harder to remember even basic stuff, like how to tie a shoe.

Eventually, the person may have trouble remembering the names and faces of family members — or even who they are. This can be very sad for the person and their family.

Alzheimer's disease does not affect kids. It usually affects people over 65 years old. Researchers have found medicines that seem to slow the disease down. And there's hope that someday there will be a cure.

What Happens in Alzheimer's Disease?

You probably know that your brain works by sending signals. Chemical messengers, called neurotransmitters (say: nur-oh-TRANS-mih-terz), allow brain cells to talk to each other. But a person with Alzheimer's disease has lower amounts of neurotransmitters.

People with Alzheimer's disease also develop deposits of stuff (protein and fiber) that prevent the cells from working properly. When this happens, the cells can't send the right signals to other parts of the brain. Over time, brain cells that are affected also begin to shrink and die.

What Causes Alzheimer's Disease?

Lots of research is being done to find out more about the causes of Alzheimer's disease. There is no one reason why people get it. Older people are more likely to get it, and the risk increases the older the person gets. In other words, an 85-year-old is more likely to get it than a 65-year-old. And women are more likely to get it than men.

Researchers also think genes handed down from family members can make a person more likely to get it. But that doesn't mean everyone related to someone who has it will get the disease. Other things may make it more likely that someone will get the disease, such as high blood pressure, high cholesterol, Down syndrome, or having a head injury.

On the positive side, researchers believe exercise, a healthy diet, and taking steps to keep your mind active (like doing crossword puzzles) may help delay the start of Alzheimer's disease.

How Do People Know They Have It?

The first sign of Alzheimer's disease is an ongoing pattern of forgetting things. This starts to affect a person's daily life. They may forget where the grocery store is or the names of family and friends. This stage may last for some time or get worse quickly, causing more severe memory loss and forgetfulness.

What Will the Doctor Do?

It can be hard for a doctor to diagnose Alzheimer's disease because many of its symptoms (like memory problems) can be like those of other conditions affecting the brain. The doctor will talk to the patient, find out about any medical problems the person has, and will examine them.

The doctor can ask the person questions or have the person take a written test to see how well their memory is working. Doctors also can use medical tests (such as MRI or CT scans) to take a detailed picture of the brain. They can study these images and look for signs of Alzheimer disease.

When a person is diagnosed with Alzheimer's disease, the doctor may prescribe medicine to help with memory and thinking. The doctor also might give the person medicine for other problems, such as depression (sad feelings that last a long time). Unfortunately, the medicines that the doctors have can't cure Alzheimer's disease; they just help slow it down.

When Someone You Love Has Alzheimer's Disease

You might feel sad or angry — or both — if someone you love has Alzheimer's disease. You might feel nervous around the person, especially if they have trouble remembering important things or can no longer take care of themselves.

You might not want to go visit the person, even though your mom or dad wants you to. You are definitely not alone in these feelings. Try talking with a parent or another trusted adult. Just saying what's on your mind might help you feel better. You also may learn that the adults in your life are having struggles of their own with the situation.

If you visit a loved one who has Alzheimer's disease, try to be patient. They may have good days and bad days. It can be sad if you can't have fun in the same ways together. Maybe you and your grandmother liked to go to concerts. If that's no longer possible, maybe bring her some wonderful music and listen together. It's a way to show her that you care — and showing that love is important, even if her memory is failing.