Alzheimer's disease (AD) is a degenerative disease of the brain, resulting in memory loss, cognitive decline, and personality changes. Alzheimer’s disease is the most common cause of dementia (loss of memory and cognitive skills). People with Alzheimer's disease first develop memory loss. As the disease progresses, memory loss worsens and problems with thinking, decision making, reasoning, language, or perception develop.
In the late stages of Alzheimer's, individuals lose their ability to communicate or respond to the environment and require constant care. The brain damage leads to the failure of the body’s organs and functions, including the lungs, heart, and digestion, which can eventually kill the individual. Alzheimer's is a disease with no cure, but there are ways to stop or slow its progression with medications and other therapies. These can treat symptoms and improve the quality of life.
Alzheimer’s disease can be either of the following:
- Sporadic Alzheimer's disease is the most common form of Alzheimer's and occurs after 65 years of age. The affected person does not have any history of the disease in their family members.
- Familial Alzheimer’s disease is a rare genetic condition. A person with inherited mutated genes may develop Alzheimer's disease when they are of age 40-50 years (early-onset).
What causes Alzheimer’s disease?
The causes of Alzheimer’s disease (AD) are unknown. Scientists believe that Alzheimer's disease may be caused by an abnormal buildup of proteins: beta-amyloid and tau. Beta-amyloid buildup forms plaques around brain cells. Tau deposits form twisted fibers called tangles within brain cells. As these proteins accumulate in and around the brain cells, the brain starts to lose its ability to function properly, this leads to loss of brain tissue, and eventually, the brain dies. The tissue damage also causes the affected parts of the brain to shrink (atrophy).
Initially plaques and tangles damage parts of the brain that control memory, thought, and language. Later they spread and damage other parts of the brain, leading to neuronal degeneration and progressive cognitive decline.
Risk factors for developing Alzheimer's disease:
The factors that increase the risk are:
- Age: Risk increases with age, affecting 15% of people older than 65 years and 50% of people older than 85 years.
- Family history: Family member with the disease increases the risk. Inherited gene mutations also increase the probability of developing the disease.
- Gender: Women have a higher risk than men.
- Down syndrome
- Traumatic head injuries earlier in life
- Other risk factors include:
What are the signs and symptoms of Alzheimer’s disease?
Alzheimer's disease is a slowly progressive disease and symptoms gradually worsen over time, interfering with daily life.
Characteristic symptoms of Alzheimer’s disease are:
- Persistent memory loss:
- Forgetting important dates or events
- Confusion and disorientation with places (getting lost)
- Confusion with date or time of the year
- Asking for the same information repeatedly
- Losing or misplacing things
- Vagueness in everyday conversation
- Cognitive decline:
- Changes in thinking skills
- Problems with decision-making, problem-solving, and planning
- Poor judgment
- Inability to process new information and questions
- Inability to follow instructions
- Difficulty performing daily tasks
- Difficulties with recognition:
- Confusion and inability to recognize faces, places, or objects
- Difficulties with language:
- Struggle in finding the right words or names of items, places, or people
- Difficulty in speaking, reading, or writing
- Difficulties with spatial awareness and visual images:
- Difficulty judging shapes and sizes
- Trouble with depth perception
- Trouble judging distances
- Vision problems
- Behavior or personality changes:
- Changes in mood, personality, or behavior
- Deterioration of social skills
- Withdrawal from social activities or work
- Disinterest in previously enjoyed activities
Latest Health and Living News
Daily Health News
Stages of Alzheimer's disease
The progression of Alzheimer’s disease is measured in seven stages:
- Stage I: No symptoms appear but early diagnosis is made based on family history.
- Stage II: Symptoms, such as absent-mindedness, appear.
- Stage III: Reduced memory and concentration appear.
- Stage IV: Memory loss with the inability to perform everyday tasks. Alzheimer’s is usually diagnosed at this stage and considered mild.
- Stage V: Moderate to severe symptoms appear.
- Stage VI: A person may need help with basic tasks, such as eating and wearing clothes.
- Stage VII: This is the final and severe stage of Alzheimer’s. Symptoms include:
- Severe memory loss, mood swings, and behavior changes
- Extreme confusion about time, place, and life events
- Trouble speaking or communicating
- Decreased physical functioning, such as walking, sitting, and swallowing
- Urinary and fecal incontinence
- Loss of facial expressions
- Suspicions about friends, family, or caregivers
How is Alzheimer’s disease diagnosed?
Currently, there is no single test to diagnose Alzheimer's disease. The diagnosis is made after a comprehensive clinical evaluation, which includes:
- Detailed health history
- Physical examination
- Neurological examination
- Psychiatric evaluation
- Neuropsychological tests
- Blood and urine test
- Cerebral spinal fluid (CSF) examination
- Imaging tests, such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) scans, of the brain
Subscribe to MedicineNet's General Health Newsletter
How is Alzheimer’s disease treated?
There is no known cure for Alzheimer’s disease. However, some drugs may help delay symptoms, slow the progression of the disease, support mental function, regulate behavior, and improve the quality of life. They are:
- The following medications are used for the treatment and management of Alzheimer's disease:
- Symptoms of behavioral changes are treated with:
- Antianxiety medications
Health Solutions From Our Sponsors
Lakhan SE. Alzheimer Disease. Medscape. https://emedicine.medscape.com/article/1134817-overview
Top How Does Alzheimer’s Kill? Related Articles
Bad Brain Health HabitsGood brain health depends on exercising regularly, eating well, and getting enough sleep. Learn how to develop good health habits to protect your brain against neurodegeneration, Alzheimer's disease, and other kinds of dementia.
Dementia: Is It Aging or Alzheimer's?Learn the difference between memory problems that can happen to all of us as we get older and real warning signs of dementia.
What Chromosome Causes Down Syndrome?Get the facts on Down syndrome, a genetic disorder caused by an additional set of chromosomes in a developing fetus. Down syndrome signs and symptoms include distinctive facial features, growth retardation, and decreased mental function and IQ. Blood tests and ultrasound may be used to screen for Down syndrome but chromosome analysis of the fetus is needed to diagnose the condition. People with Down syndrome age more quickly and may develop Alzheimer's disease as young as age 40. Sometimes people are diagnosed with mosaic Down syndrome, in which case they have more than one type of chromosomal makeup.
Why Do I Forget Things Easily?Forgetting things is quite common. You may forget things easily due to aging, Alzheimer's disease, stress, head injury, medications and other reasons.