Please note: This slide show is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always consult your doctor about any questions you may have regarding a medical condition.
What is Alzheimer's disease?
Alzheimer's disease is a brain disease that slowly destroys memory and thinking skills. It is a progressive disease, which means it gets worse over time.
Alzheimer's disease is irreversible. People with Alzheimer's eventually lose the ability to carry out the simplest of tasks.
Alzheimer's is the most common cause of dementia among people aged 65 and older. Dementia is loss of the ability to think and remember things that is severe enough that a person has trouble doing day-to-day activities.
What is Alzheimer's disease?
About 5.8 million people in the United States have Alzheimer's disease.
Rarely, people younger than 65 can have Alzheimer's. This is called early-onset Alzheimer's disease. Around one of every 20 people with Alzheimer's have early-onset Alzheimer's disease.
What is Alzheimer's disease?
You're more likely to get Alzheimer's if one or more of your close family members – parents, brothers, or sisters – has it.
Common early symptoms of Alzheimer's disease
The most common early symptom of Alzheimer's disease is trouble remembering recent events.
Other early symptoms may include
Having trouble completing daily tasks, and
Getting lost when driving on a route the person used to know well
These symptoms are not the same as normal forgetfulness, which can happen to all of us as we get older. For example, if you sometimes forget about an appointment, forget a person's name, or misplace your keys, it doesn't mean you have Alzheimer's.
Symptoms of mild Alzheimer's disease
A person with mild Alzheimer's disease may
Need help with usual tasks (like managing finances, planning meals, and keeping appointments)
Have trouble sleeping, and
Become anxious or depressed.
Symptoms of moderate Alzheimer's disease
– When Alzheimer's disease worsens
As symptoms of Alzheimer's disease get worse, a person may
Have some trouble recognizing family members and friends.
Need help with daily activities like getting dressed.
Become fearful or suspicious of other people.
Believe they are seeing or hearing things that aren't real.
Symptoms of severe Alzheimer's disease – When Alzheimer's disease becomes severe
When Alzheimer's disease becomes severe, a person loses much of their ability to communicate and needs full-time help to take care of themselves.
What causes Alzheimer's disease?
Doctors don't fully understand what causes Alzheimer's disease in most people.
Most people with Alzheimer's disease are older, but just getting older doesn't cause the disease. Many people live well into their 90s without getting Alzheimer's disease.
What causes Alzheimer's disease? – Genes associated with Alzheimer's disease
Carrying a variant of a gene known as APOE increases a person's risk for Alzheimer's disease, especially the late-onset form of the disease. But not everyone who has this gene gets the disease, and people who don't have the gene can still get the disease.
Early-onset Alzheimer's disease can also be caused by an inherited change in one of three other genes, yet these genes are very uncommon.
What causes Alzheimer's disease? – Conditions that may increase risk for Alzheimer's disease
Other conditions that may increase risk for Alzheimer's disease include
Smoking
Diabetes
High blood pressure
An unhealthy diet
What happens in the brain in Alzheimer's disease?
Doctors now know that changes begin happening in the brain 10-20 years or more before a person with Alzheimer's disease shows any symptoms.
Neurons are brain cells that send and receive signals to and from the brain. Everything we do as living beings – walking, thinking, forming memories – happens because of these signals. A healthy adult brain contains about 100 billion neurons.
What happens in the brain in Alzheimer's disease?
When a person has Alzheimer's disease, tiny pieces of a protein called beta amyloid build up in between neurons, forming clusters, or plaques.
What happens in the brain in Alzheimer's disease?
Another protein, called tau, builds up inside neurons, forming dense, thread-like tangles.
Together, these plaques and tangles block neurons from sending and receiving signals.
What happens in the brain in Alzheimer's disease?
Because of these and other abnormal changes in the brain, neurons start to die. The first place this happens is in the parts of the brain where memories are formed.
As more neurons die, the brain starts to shrink. As Alzheimer's gets worse over time, the brain may shrink to about a third of its normal size.
What is mixed dementia?
Mixed dementia is dementia that's caused by brain changes due to Alzheimer's disease and one or more other brain diseases.
For example, a person may have dementia that's caused by both Alzheimer's disease and Parkinson's disease.
What is vascular dementia?
A person may also have both Alzheimer's disease and vascular dementia. This type of dementia occurs when the brain gets less blood than it needs. This can happen after a person has had a series of small strokes.
Can Alzheimer's disease be prevented?
Studies show there are steps you can take to reduce your risk for Alzheimer's disease.
Don't smoke.
Keep your body and your mind active.
Stay in touch with family and friends.
Eat a healthy diet.
Can Alzheimer's disease be prevented?
Maintain a healthy weight.
Control high blood pressure.
Drink alcohol in moderation.
Drink coffee in moderation.
Can Alzheimer's disease be prevented?
Recent studies suggest that getting vaccinated against pneumonia and the flu can also help lower your risk for Alzheimer's disease.
References
National Institute on Aging. Alzheimer's Disease Fact Sheet. https://www.nia.nih.gov/health/alzheimers-disease-fact-sheet. Reviewed 5/22/2019.
National Institute of Neurological Disorders and Stroke. Alzheimer's Disease Information Page. Definition. https://www.ninds.nih.gov/Disorders/All-Disorders/Alzheimers-Disease-Information-Page. Last modified 3/27/2019.
Alzheimer's Association. 2020 Alzheimer's Disease Facts and Figures. https://www.alz.org/media/Documents/alzheimers-facts-and-figures.pdf.
Zhu XC, Tan L, Wang HF, et al. Rate of early onset Alzheimer's disease: a systematic review and meta-analysis. Ann Transl Med 2015;3:38.
National Institute on Aging. Alzheimer's and Hallucinations, Delusions, and Paranoia. https://www.nia.nih.gov/health/alzheimers-and-hallucinations-delusions-and-paranoia. Reviewed 5/17/2017.
National Institute on Aging. Alzheimer's Disease Genetics Fact Sheet. https://www.nia.nih.gov/health/alzheimers-disease-genetics-fact-sheet. Reviewed 12/24/2019.
Dementia Care Central. Normal Brain vs. Alzheimer's. https://www.dementiacarecentral.com/video/video-brain-changes/.
National Institute on Aging. What Do We Know About Diet and Prevention of Alzheimer's Disease? https://www.nia.nih.gov/health/what-do-we-know-about-diet-and-prevention-alzheimers-disease. Reviewed 11/27/2019.
Livingston G, Sommerlad A, Orgeta V, et al. Dementia prevention, intervention, and care. Lancet. 2017;390(10113):2673-2734. doi:10.1016/S0140-6736(17)31363-6
The SPRINT MIND Investigators for the SPRINT Research Group. Effect of Intensive vs Standard Blood Pressure Control on Probable Dementia: A Randomized Clinical Trial. JAMA. 2019;321(6):553–561. doi:10.1001/jama.2018.21442
Driscoll I, Shumaker SA, Snively BM, et al. Relationships Between Caffeine Intake and Risk for Probable Dementia or Global Cognitive Impairment: The Women's Health Initiative Memory Study. J Gerontol A Biol Sci Med Sci. 2016;71(12):1596-1602. doi:10.1093/gerona/glw078
Alzheimer's Association. Flu, Pneumonia Vaccinations Tied to Lower Risk of Alzheimer's Dementia [press release]. 2020 July 27. https://www.alz.org/aaic/releases_2020/vaccines-dementia-risk.asp
Slide Show - Understanding Alzheimer's Disease
Alzheimer's disease is a brain disease that slowly destroys memory and thinking skills. It is a progressive disease, which means it gets worse over time. Alzheimer's is the most common cause of dementia among people aged 65 and older. Rarely, people younger than 65 can have Alzheimer's. This is called early-onset Alzheimer's disease. This slide show explains the symptoms, causes and risk factors of Alzheimer's disease, as well as what happens in the brain in Alzheimer's disease. This slide show also describes mixed dementia, and the steps you can take to reduce your risk for Alzheimer's disease.
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Jointly provided by the Annenberg Center for Health Sciences at Eisenhower and Prime Medic Inc., in collaboration with Postgraduate Institute for Medicine.
This activity is supported by an independent educational grant from Biogen Idec.
This website is part of the Animated Patient™ series developed by Prime Medic Inc., to provide highly visual formats of learning for patients to improve their understanding, make informed decisions, and partner with their healthcare professionals for optimal outcomes.
