The global incidence of dementia is estimated at 24 million individuals, which is expected to double by 2060. Alzheimer disease is predicted to cost $172 billion in health care costs in the United States annually. After the age of 65, the risk of Alzheimer increases every five years.

The primary risk factor for Alzheimer’s disease is advancing age. Traumatic brain injury, depression, cardiovascular and cerebrovascular disease, older parental age, smoking, family history of dementia, elevated homocysteine levels, and the presence of the APOE e4 allele have all been linked to an increased risk of Alzheimer disease.

Alzheimer disease is a specific condition, but dementia is a broad term for a deterioration in mental ability severe enough to impair daily life. The most common contributor to dementia is Alzheimer disease.

Although low amyloid and high tau proteins in CSF serve as biomarkers, they are not exclusive to Alzheimer’s disease. A person may function independently in the early stages of Alzheimer’s. He or she may continue to drive, work, and participate in social events.

Despite this, the individual may experience memory lapses, such as forgetting familiar words or placing everyday objects. The progression to mild cognitive impairment can be predicted by increasing tau protein in CSF, right entorhinal cortex thickness, and right hippocampus volume on MRI.

Patients’ memory or nonmemory areas, such as executive ability or language function, are impaired. The individuals continue to work, socialize, and operate on their own.

Patients with mild cognitive impairment develop dementia at a rate of 10% yearly. According to a national survey, stress is the leading cause of mild cognitive impairment, particularly in individuals under 50.

Patients in this stage have severe memory and language impairment, such as anomia, paraphrasing errors, a decline in spontaneous verbal output, and a propensity for circumlocution to avoid forgotten words. Wandering in familiar settings and constructional apraxia result from impaired visuospatial ability.

Delusions occur in 20–40% of patients. Although patients also have olfactory and auditory hallucinations, visual hallucinations are more frequent. Nearly 50% of patients engage in disruptive behaviors. Patients also experience interrupted sleep and lose their regular circadian sleep-wake pattern.

Men and women with Alzheimer disease experience different cognitive and psychiatric symptoms. Women undergo faster cognitive decline after diagnoses with mild cognitive impairment or dementia.

Brain atrophy rates and patterns differ between genders along the disease continuum; in mild cognitive impairment, brain atrophy is more rapid in women than in men.

Men and women have differing prevalence and impact of metabolic, cerebrovascular, and socioeconomic risk factors for Alzheimer’s disease.

Alzheimer disease is initially associated with decreased memory; nevertheless, the individual may acquire significant cognitive and behavioral symptoms such as depression, rage, anxiety, irritability, sleeplessness, and paranoia with time.

Most individuals will require assistance with daily living activities as the disease advances. Even walking becomes difficult at some point, and many patients cannot eat or suffer from swallowing issues, leading to aspiration pneumonia.

Most patients with Alzheimer disease are older adults, while it can also afflict individuals in their 30s or 40s. Early-onset (or younger-onset) Alzheimer disease is the term used to describe the disease that develops in people under the age of 65.

The early-onset variant of Alzheimer’s affects a relatively small percentage of people. When the condition begins to spread, many patients are in their 40s and 50s.

13% of familial early onset Alzheimer disease instances are autosomal dominant, affecting at least three generations. Most Alzheimer’s cases tend to be complicated, involving numerous susceptibility genes and environmental variables.

Although the lifetime risk of the disease is about twice as high for first-degree relatives of individuals with late-onset disease, the pattern of transmissions is rarely consistent with Mendelian inheritance.

• Memory loss that disrupts daily life, difficulty completing familiar tasks at home or work.
• Confusion with time or place
• Challenges in planning or solving problems
• New problems with words in speaking or writing, decreased or poor judgment
• Misplacing things and losing the ability to retrace steps
• Withdrawal from work or social activities, changes in mood and personality