Alzheimer’s disease is the most common type of dementia, an irreversible and progressive brain disorder that slowly destroys memory and thinking skills, and eventually the ability to carry out the simplest tasks.
Dementia is a progressive neurological disease that affects multiple brain functions, including memory.
In most people with Alzheimer’s, symptoms first appear in the mid-1960s.
Causes of Alzheimer’s disease
Alzheimer’s disease is caused by the shrinkage of parts of the brain (atrophy), which affects the structure and function of certain areas of the brain.
It is not known exactly what causes this process.
However, in the brains of people with Alzheimer’s disease, scientists have found several abnormal processes:
- Deposits of a special type of protein called amyloid plaques
- Neurofibrillary tangles that contain a protein called tau
- Imbalances in a chemical called acetylcholine.
- Vascular damage to the brain, which damages healthy neurons (nerve cells that carry messages to and from the brain), gradually destroying them.
Over time vascular damage spreads to various areas of the brain.
The first affected areas are responsible for the memories.
Risk factors for developing the disease
Although what triggers Alzheimer’s disease is still unknown, several factors are known to increase the risk of developing the disease.
Age is the most important factor in the development of Alzheimer’s disease. The chance of developing the disease doubles every five years after age 65.
However, it is not only the elderly who are at risk of developing Alzheimer’s disease.
About 1 in 20 people with the condition are under the age of 65.
This is called early-onset Alzheimer’s disease, and it can affect people around the age of 40.
Genes that you inherit from your parents can contribute to your risk of developing Alzheimer’s disease, although the actual increase in risk is small if you have a close family member with the condition.
However, in some families, Alzheimer’s disease is caused by the inheritance of a single gene, and the risks of the condition being transmitted are much higher.
If several of your family members have developed dementia over the generations, it may be appropriate to seek genetic counseling for information and advice on your chances of developing Alzheimer’s disease when you are older.
People with Down syndrome have a higher risk of developing Alzheimer’s disease.
This is because the genetic flaw that causes Down syndrome can also cause amyloid plaques to build up in the brain over time, which can lead to Alzheimer’s disease.
People who have suffered severe head trauma have been found to be at higher risk of developing Alzheimer’s disease.
Several lifestyle factors and conditions associated with cardiovascular disease can increase the risk of Alzheimer’s disease.
At first, increasing forgetfulness or mild confusion may be the only symptoms of Alzheimer’s disease.
But over time, the disease affects memory more, especially recent memories. The worsening of symptoms varies from person to person.
The person with Alzheimer’s may be the first to notice that they are having unusual difficulties remembering things and organizing their thoughts.
Or you may not recognize that something is wrong, even when the changes are noticeable to your family members, close friends, or coworkers.
The brain changes associated with Alzheimer’s disease lead to increasing problems with:
Everyone has occasional memory lapses. It is normal to lose track of where you put your keys or to forget the name of someone you know.
But the memory loss associated with Alzheimer’s disease persists and worsens, affecting a person’s ability to function at work and at home.
People with Alzheimer’s can:
- Repeating statements and questions over and over again, not realizing that they have asked the question before.
- Forgetting conversations, appointments or events, and not remembering them later.
- Leaving possessions lost, often putting them in illogical locations.
- Get lost in familiar places.
- Eventually forgetting the names of family members and everyday objects.
- Have trouble finding the right words to identify objects, express thoughts, or participate in conversations.
Thinking and reasoning
Alzheimer’s disease causes difficulty concentrating and thinking, especially about abstract concepts like numbers.
Multitasking is especially difficult, and it can be challenging to manage finances and pay bills on time.
These difficulties can progress to the inability to recognize and deal with numbers.
Make judgments and make decisions
Responding effectively to everyday problems, such as burning food on the stove or unexpected driving situations, becomes increasingly difficult.
Planning and performing family tasks
Routine activities that require sequential steps, such as planning and cooking a meal or playing a favorite game, turn into a struggle as the disease progresses.
Eventually, people with advanced Alzheimer’s may forget how to perform basic tasks like dressing and bathing.
Changes in personality and behavior
The brain changes that occur in Alzheimer’s disease can affect the way you act and feel.
People with Alzheimer’s can experience:
- Social retreat
- Humor changes
- Mistrust in others
- Irritability and aggressiveness
- Changes in sleeping habits
- Loss of inhibitions
- Delusions, like believing that something has been stolen
Many important skills are not lost until very late in the illness.
These include the ability to read, dance, and sing, enjoy music, engage in crafts, play hobbies, or tell stories.
The part of the brain that stores this information tends to be affected later in the course of the disease.
Capitalizing on these skills can promote successes and maintain quality of life even in the moderate phase of the disease.