Brain health basics, in plain language.
Science-based facts and a simple glossary to help you understand your brain and care for it.
Brain Health Fact #1
The brain is arguably the most important organ in the human body. It controls and coordinates actions and reactions, movement, allows us to think and feel, and enables us to have memories and feelings—all the things that give us our unique personality. However, the prevalence of brain disease and cognitive impairment is startlingly high and continues to grow.
Brain Health Fact #2
More than 10 million people worldwide are living with PD.
Brain Health Fact #3
Neurodegenerative diseases affect millions of people worldwide. Alzheimer’s disease and Parkinson’s disease are the most common neurodegenerative diseases. In the United States, as many as 6.2 million people may have Alzheimer’s disease, according to a report from the Alzheimer's Disease Association in 2022. Nearly a million Americans are living with Parkinson’s disease, according to the Parkinson’s Foundation.
Brain Health Fact #4
In the United States, around 1.7 million people suffer a traumatic brain injury, with adolescents between ages 15 and 19 and adults aged 65 and older among the most likely to sustain a traumatic brain injury. Mild traumatic brain injury (mTBI), also known as a brain concussion, initially was considered to be a benign occurrence.
Brain Health Fact #5
Dementia is not a single disease. Instead, dementia is an umbrella term that describes a collection of symptoms. These symptoms are caused by the deterioration of brain tissue, which is normally caused by a build-up of toxic proteins. Over 50 conditions are known to cause the symptoms of dementia.
Brain Health Fact #6
Because of a property called neuroplasticity, the brain is constantly changing in response to the experience. Neuroplasticity is one of the brain’s most important properties, as it lets us learn and adapt to our environment. Plasticity can occur in many ways: synapses – the junctions between neurons – can change strength (a bit like changing the volume of a conversation), new synapses can appear or disappear, and in some parts of the brain, brand-new neurons can be born.
Brain Health Fact #7
Everyday habits like exercise and eating right can lower risks for memory loss and other symptoms of cognitive decline, research suggests. Studies have also found that managing blood pressure and blood sugar can benefit the brain — the same goes for sleep and social engagement.
Brain Health Fact #8
Our brains and bodies regulate our sleep and circadian rhythms. Equally so, our sleep and circadian rhythms affect our brains and bodies. Sleep disturbances have a broad impact on our health and body functions. They’re also linked to an increased risk for disease, including neurodegenerative disorders like Alzheimer’s and Parkinson’s. Some data indicate that sleep and circadian rhythm dysfunction, such as fragmented sleep or night wakings, may be risk factor for these types of brain diseases.
Alzheimer’s Disease:
An irreversible, progressive brain disorder that slowly destroys memory and thinking skills and, eventually, the ability to carry out the simplest tasks. Symptoms usually develop slowly and get worse over time, becoming severe enough to interfere with daily tasks.
Alzheimer’s Dementia:
The dementia stage in the Alzheimer’s continuum.
Brain Health:
A concept that involves making the most of the brain’s capacity and helping to reduce some risks that occur with aging. Brain health is the ability to draw on the brain's strengths to remember, learn, play, concentrate, and maintain a clear, active mind.
Care Partner:
Spouses, partners, adult children, other relatives, and friends provide unpaid help to people living with dementia who have at least one limitation in their activities of daily living and reside in the community. Caregivers often assist with diverse activities of daily living such as personal care, household management, medication and healthcare management, and coordination of financial matters.
Chronic traumatic encephalopathy (CTE):
A progressive brain condition thought to be caused by repeated blows to the head and repeated episodes of concussion. It's particularly associated with contact sports, such as boxing or American football. Most of the available studies are based on ex-athletes.
Cognition:
The mental functions involved attention, thinking, understanding, learning, remembering, solving problems, and making decisions. Cognition is a fundamental aspect of an individual’s ability to engage in activities, accomplish goals, and successfully negotiate the world. It can be viewed along a continuum—from optimal functioning to mild cognitive impairment to Alzheimer’s and severe dementia.
Cognitive Impairment:
Trouble remembering, learning new things, concentrating, or making decisions that affect everyday life.
Dementia:
The loss of cognitive functioning—thinking, remembering, and reasoning—and behavioral abilities to such an extent that it interferes with a person’s daily life and activities. These functions include memory, language skills, visual perception, problem-solving, self-management, and the ability to focus and pay attention. Alzheimer’s is the most common cause of dementia. Other types include vascular dementia, dementia with Lewy bodies, and frontotemporal dementia.
Mild Cognitive Impairment:
A slight but measurable decline in cognitive abilities, including memory and thinking. A person with mild cognitive impairment is at an increased risk of developing Alzheimer’s or another dementia.
Subjective Cognitive Decline:
Self-reported confusion or memory loss that is happening more often or is getting worse.
Neurodegenerative Diseases (known as Degenerative Nerve Disease):
Affect many of your body's activities, such as balance, movement, talking, breathing, and heart function. Many of these diseases are genetic. Sometimes the cause is a medical condition such as alcoholism, a tumor, or a stroke. Other causes may include toxins, chemicals, and viruses. Sometimes the cause is unknown.
Degenerative nerve diseases include:
Alzheimer's disease
Amyotrophic lateral sclerosis
Friedreich ataxia
Huntington's disease
Lewy body disease
Parkinson's disease
Spinal muscular atrophy
Neuroplasticity:
The ability of the brain to form and reorganize synaptic connections, especially in response to learning or experience or following an injury.
Traumatic Brain Injury (TBI):
An injury that affects how the brain works. TBI is a major cause of death and disability in the United States. Anyone can experience a TBI, but data suggest that some groups are at greater risk of getting a TBI or having worse health outcomes after the injury.