Alzheimer’s

Alzheimer’s disease is a progressive form of dementia. Dementia is a broader term for conditions that negatively affect memory, thinking, and behavior. The changes interfere with daily living. Dementia can have a range of causes, such as brain injuries or diseases. Sometimes the cause is unknown.

According to the Alzheimer’s Association, Alzheimer’s disease accounts for 60 to 80 percent of dementia cases. Most people with the disease get a diagnosis after age 65. If it’s diagnosed before then, it’s generally referred to as “younger onset” or “early onset” Alzheimer’s disease.

There’s no cure for Alzheimer’s, but there are treatments that can slow the progression of the disease.

The symptoms of Alzheimer's disease progress slowly over several years. Sometimes these symptoms are confused with other conditions and may initially be put down to old age.

The rate at which the symptoms progress is different for each individual.

In some cases, other conditions can be responsible for symptoms getting worse.

These conditions include:

infections

stroke

delirium

As well as these conditions, other things, such as certain medicines, can also worsen the symptoms of dementia.

Anyone with Alzheimer's disease whose symptoms are rapidly getting worse should be seen by a doctor so these can be managed.

There may be reasons behind the worsening of symptoms that can be treated

Stages of Alzheimer's disease

Generally, the symptoms of Alzheimer's disease are divided into 3 main stages.

Early symptoms

In the early stages, the main symptom of Alzheimer's disease is memory lapses.

For example, someone with early Alzheimer's disease may:

forget about recent conversations or events

misplace items

forget the names of places and objects

have trouble thinking of the right word

ask questions repetitively

show poor judgement or find it harder to make decisions

become less flexible and more hesitant to try new things

There are often signs of mood changes, such as increasing anxiety or agitation, or periods of confusion.

Middle-stage symptoms

As Alzheimer's disease develops, memory problems will get worse.

Someone with the condition may find it increasingly difficult to remember the names of people they know and may struggle to recognise their family and friends.

Other symptoms may also develop, such as:

increasing confusion and disorientation – for example, getting lost, or wandering and not knowing what time of day it is

obsessive, repetitive or impulsive behaviour

delusions (believing things that are untrue) or feeling paranoid and suspicious about carers or family members

problems with speech or language (aphasia)

disturbed sleep

changes in mood, such as frequent mood swings, depression and feeling increasingly anxious, frustrated or agitated

difficulty performing spatial tasks, such as judging distances

seeing or hearing things that other people do not (hallucinations)

Some people also have some symptoms of vascular dementia.

By this stage, someone with Alzheimer's disease usually needs support to help them with everyday living.

For example, they may need help eating, washing, getting dressed and using the toilet.

Later symptoms

In the later stages of Alzheimer's disease, the symptoms become increasingly severe and can be distressing for the person with the condition, as well as their carers, friends and family.

Hallucinations and delusions may come and go over the course of the illness, but can get worse as the condition progresses.

Sometimes people with Alzheimer's disease can be violent, demanding and suspicious of those around them.

A number of other symptoms may also develop as Alzheimer's disease progresses, such as:

difficulty eating and swallowing (dysphagia)

difficulty changing position or moving around without assistance

weight loss – sometimes severe

unintentional passing of urine (urinary incontinence) or stools (bowel incontinence)

gradual loss of speech

significant problems with short- and long-term memory

In the severe stages of Alzheimer's disease, people may need full-time care and assistance with eating, moving and personal care.

The exact causes of Alzheimer's disease aren't fully understood. But at a basic level, brain proteins fail to function normally, which disrupts the work of brain cells (neurons) and triggers a series of toxic events. Neurons are damaged, lose connections to each other and eventually die.

Scientists believe that for most people, Alzheimer's disease is caused by a combination of genetic, lifestyle and environmental factors that affect the brain over time.

Less than 1% of the time, Alzheimer's is caused by specific genetic changes that virtually guarantee a person will develop the disease. These rare occurrences usually result in disease onset in middle age.

The damage most often starts in the region of the brain that controls memory, but the process begins years before the first symptoms. The loss of neurons spreads in a somewhat predictable pattern to other regions of the brains. By the late stage of the disease, the brain has shrunk significantly.

Researchers trying to understand the cause of Alzheimer's disease are focused on the role of two proteins:

Plaques. Beta-amyloid is a fragment of a larger protein. When these fragments cluster together, they appear to have a toxic effect on neurons and to disrupt cell-to-cell communication. These clusters form larger deposits called amyloid plaques, which also include other cellular debris.

Tangles. Tau proteins play a part in a neuron's internal support and transport system to carry nutrients and other essential materials. In Alzheimer's disease, tau proteins change shape and organize themselves into structures called neurofibrillary tangles. The tangles disrupt the transport system and are toxic to cells.

Increasing age is the greatest known risk factor for Alzheimer's disease. Alzheimer's is not a part of normal aging, but as you grow older the likelihood of developing Alzheimer's disease increases.

One study, for example, found that annually there were four new diagnoses per 1,000 people ages 65 to 74, 32 new diagnoses per 1,000 people ages 75 to 84, and 76 new diagnoses per 1,000 people age 85 and older.

Family history and genetics

Your risk of developing Alzheimer's is somewhat higher if a first-degree relative — your parent or sibling — has the disease. Most genetic mechanisms of Alzheimer's among families remain largely unexplained, and the genetic factors are likely complex.

One better understood genetic factor is a form of the apolipoprotein E gene (APOE). A variation of the gene, APOE e4, increases the risk of Alzheimer's disease. Approximately 25% to 30% of the population carries an APOE e4 allele, but not everyone with this variation of the gene develops the disease.

Scientists have identified rare changes (mutations) in three genes that virtually guarantee a person who inherits one of them will develop Alzheimer's. But these mutations account for less than 1% of people with Alzheimer's disease.

Down syndrome

Many people with Down syndrome develop Alzheimer's disease. This is likely related to having three copies of chromosome 21 — and subsequently three copies of the gene for the protein that leads to the creation of beta-amyloid. Signs and symptoms of Alzheimer's tend to appear 10 to 20 years earlier in people with Down syndrome than they do for the general population.

Sex

There appears to be little difference in risk between men and women, but, overall, there are more women with the disease because they generally live longer than men.

Mild cognitive impairment

Mild cognitive impairment (MCI) is a decline in memory or other thinking skills that is greater than normal for a person's age, but the decline doesn't prevent a person from functioning in social or work environments.

People who have MCI have a significant risk of developing dementia. When the primary MCI deficit is memory, the condition is more likely to progress to dementia due to Alzheimer's disease. A diagnosis of MCI encourages a greater focus on healthy lifestyle changes, developing strategies to make up for memory loss and scheduling regular doctor appointments to monitor symptoms.

Head trauma

People who've had a severe head trauma have a greater risk of Alzheimer's disease. Several large studies found that in people age 50 years or older who had a traumatic brain injury (TBI), the risk of dementia and Alzheimer's disease increased. The risk increases in people with more-severe and multiple TBIs. Some studies indicate that the risk may be greatest within the first six months to two years after the TBI.

Air pollution

Studies in animals have indicated that air pollution particulates can speed degeneration of the nervous system. And human studies have found that air pollution exposure — particularly from traffic exhaust and burning wood — is associated with greater dementia risk.

Excessive alcohol consumption

Drinking large amounts of alcohol has long been known to cause brain changes. Several large studies and reviews found that alcohol use disorders were linked to an increased risk of dementia, particularly early-onset dementia.

Poor sleep patterns

Research has shown that poor sleep patterns, such as difficulty falling asleep or staying asleep, are associated with an increased risk of Alzheimer's disease.

Lifestyle and heart health

Research has shown that the same risk factors associated with heart disease may also increase the risk of Alzheimer's disease. These include:

Lack of exercise

Obesity

Smoking or exposure to secondhand smoke

High blood pressure

High cholesterol

Poorly controlled type 2 diabetes

These factors can all be modified. Therefore, changing lifestyle habits can to some degree alter your risk. For example, regular exercise and a healthy low-fat diet rich in fruits and vegetables are associated with a decreased risk of developing Alzheimer's disease.

Lifelong learning and social engagement

Studies have found an association between lifelong involvement in mentally and socially stimulating activities and a reduced risk of Alzheimer's disease. Low education levels — less than a high school education — appear to be a risk factor for Alzheimer's disease.

Memory and language loss, impaired judgment and other cognitive changes caused by Alzheimer's can complicate treatment for other health conditions. A person with Alzheimer's disease may not be able to:

Communicate that he or she is experiencing pain

Explain symptoms of another illness

Follow a prescribed treatment plan

Explain medication side effects

As Alzheimer's disease progresses to its last stages, brain changes begin to affect physical functions, such as swallowing, balance, and bowel and bladder control. These effects can increase vulnerability to additional health problems such as:

Inhaling food or liquid into the lungs (aspiration)

Flu, pneumonia and other infections

Falls

Fractures

Bedsores

Malnutrition or dehydration

Constipation or diarrhea

Dental problems such as mouth sores or tooth decay

Alzheimer’s is one of the diseases people most want to avoid, and for good reason. There is no proven way to prevent it. But there’s a lot you can do to lower your chance of getting it.

Doctors don’t know exactly why the disease strikes some people and not others, why it gets worse over the years, or how to cure it. And because they don’t know the answers to these questions, they also aren’t totally sure how to treat it.

It’s true that Alzheimer’s becomes more common with age. But it’s not a normal part of getting older. It’s also true that some gene glitches make you more likely to get it.

You can’t control aging or your genes, but that doesn’t mean you can’t do anything about the disease. In fact, the same things that are good for your heart -- and the rest of your body -- could also help you make Alzheimer’s disease less likely. And a lot of it comes down to simple things you do every day.

Manage your numbers. Do you know if your blood pressure, blood sugar, and cholesterol are too high? Research shows strong connections between Alzheimer’s and conditions like high blood pressure, high cholesterol, type 2 diabetes, and heart disease. A lot of people don’t know that they have these conditions. A checkup could let you know. And you and your doctor can work to manage any health problems you have.

Check your weight. If you have a lot of weight to lose, and start to work on shedding those pounds and keeping them off, it also could help lower your risk. One study found that obesity can change the brain in a way that raises your odds of getting Alzheimer’s.

Exercise your body. When you work out, even a little bit, more blood flows to the brain, which makes your brain healthier. Aim for at least 30 minutes of exercise, 5 or more days per week