Definition and Overview

Alzheimer’s disease is a chronic neurodegenerative condition and one of the major causes of dementia, a persistent disorder of the mental processes marked by impaired reasoning and memory disorders. Many patients and experts report that one of the early symptoms of the condition is short-term memory loss, with potential Alzheimer’s patients being unable to remember details of recent events.

In the past, Alzheimer’s is thought to be caused by advanced age. However, a German psychiatrist named Alois Alzheimer performed a case study on a middle-aged woman from 1901 to 1906. This was the first identified case of the condition, and succeeding medical literatures related to the case referred to the condition as Alzheimer’s disease. Emil Kraepelin further described the condition in the 1910 edition of Textbook of Psychiatry, where he also referred to Alzheimer’s disease as “presenile dementia.”

Alzheimer’s disease is one of the costliest diseases in many parts of the world, including Europe, the Americas, and Asia. As there is no direct way to treat the condition as of the moment, many patients have to be placed in nursing homes or under the care of full-time professional caregivers.

Cause of Condition

The cause of Alzheimer’s disease is still highly debated among experts in the field. With the exception of up to five percent of all known cases, medical experts are still unable to pinpoint the specific causes.

In five percent of Alzheimer’s cases, genetics seems to be the most probable cause. Research shows that having a parent with Alzheimer’s disease makes an individual up to 79% more likely to inherit the disease. In some cases, Alzheimer’s disease is a dominant inheritance trait and is likely to manifest before the individual reaches 65 years old—this is known as early onset familial Alzheimer’s disease.

On the other hand, the majority of cases do not exhibit the circumstance associated with early onset familial Alzheimer’s. Known as sporadic Alzheimer’s disease, the individual’s likelihood to develop the condition is greatly affected by the environment, which, when combined with genetic risk factors, can manifest in some members of the family while being absent in other family members.

Geneticists have discovered mutations in certain genes that contribute to the risk factor of Alzheimer’s disease. For example, a TREM2 gene mutation can increase the individual’s risk of developing the condition up to five times higher. Research shows that this specific mutation prevents the individual’s white blood cells from effectively controlling the presence of beta amyloid in the brain.

Other causes of Alzheimer’s disease remain to be mere hypotheses. One of the most popular is the cholinergic hypothesis, which states that Alzheimer’s disease is caused by the reduced production of acetylcholine, a neurotransmitter. Many medication and treatments for the condition are based on this presumption. On the other hand, some experts support the amyloid hypothesis, which postulates that the presence of extracellular amyloid beta in the brain causes Alzheimer’s disease. In recent years, further research shows that a relative of this amyloid protein is indeed the cause of the condition. There are many other hypotheses proposed by medical experts and researchers, but up to this day, no concrete answers have surfaced.

Key Symptoms

One of the main reasons why Alzheimer’s disease is not immediately diagnosed is because the early symptoms are, more often than not, dismissed as a sign of stress or a part of the natural aging process. Research shows that early symptoms are hard to detect, since findings present that mild cognitive difficulties (such as failing to remember certain things, events, names, etc.) do not automatically qualify the patient as an Alzheimer’s disease sufferer. It might take up to eight years of disease progression before a medical professional can, with 100% certainty, diagnose an Alzheimer’s in a patient.

Early symptoms of the condition include an increasing difficulty to remember things and impaired learning. Some patients also have language difficulties, agnosia (the inability to recognize certain sensory information, such as shapes, sounds, persons, scents, etc), lack of focus, and limited abstract thinking, as well as problems with memory (short-term memory and semantic memory are the most commonly affected). There are also cases where the individual suffers from decreased word fluency and fine motor skills.

As the disease progresses, Alzheimer’s patients can observe the worsening of earlier symptoms. For example, the individual may have language difficulties and unable to recall vocabulary words. The patient's reading, writing, and motor skills, as well as balance and long-term memory, may also be severely affected. At this stage, the Alzheimer’s patient exhibits noticeably changed behaviour. They can be more irritable and emotionally unstable, aggressive, delusional, and incontinent.

When the disease has advanced, the patient will have very limited linguistic and motor activities. The patient will also be more exhausted and even apathetic about the things he/she used to enjoy or care about. Without help, patients with advanced stage of Alzheimer’s can no longer perform ordinary tasks. While Alzheimer’s disease does not usually lead to death, it can make the patient susceptible to pneumonia, pressure ulcers, and other similarly fatal conditions.

Who to See and Types of Treatments Available

Currently, there is no available cure for Alzheimer’s disease. Usually, treatments offered to sufferers can slightly improve their current conditions but they are palliative in nature. Medication can be prescribed to offer temporary relief from physical pain, symptoms, and stress.

Most patients have to be put under the care of professional caregivers, either in a nursing home or in their own residences. Caregivers assist the patients in most of the things they do, and can be expected to help manage the disease.


  • Alzheimer's Association -
  • Alzheimer's Disease Education and Referral Center -
  • Alzheimer's Disease Research -
  • Alzheimer' -
  • U.S. Centers for Disease Control and Prevention -
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