Dementia is a chronic or persistent disorder of the mental processes caused by brain disease or injury. It is not a specific disease, but rather, it is classified as a collective group of symptoms that affect social and mental health. It also affects behavior and the ability to perform everyday activities The chances of contracting dementia increase exponentially after age 60 and usually worsens over time.  "Dementia affects about 1% of people between ages 60 and 64, 5-8% of all people between ages 65 and 74, up to 20% of those between 75 and 84, and between 30% and 50% of those age 85 and older. About 60% of nursing home patients have dementia." 
Various factors induce dementia. The components vary from age, side-effects of disease, infection, stroke, injuries sustained to the head, the reaction, overuse, or abuse of drugs, lack of oxygen to the brain, or vitamin deficiencies. Dementia is commonly generated by the dysfunction or disruption of the cerebral cortex or subsections of the brain that coordinate cerebral cortex function.  “The cerebral cortex is responsible for the processes of thought, perception, and memory and serves as the seat of advanced motor function, social abilities, language, and problem solving.”  Within the category of dementia rests two subsidiary divisions: irreversible and reversible dementia. 
Eight examples of irreversible dementia include Alzheimer’s disease, Parkinson’s disease, Lewy body disease, Huntington’s disease, Creutzfeldt-jakob’s disease, vascular dementia , and chronic traumatic encephalopathy.  Irreversible dementia can also be termed as a case of dementia that may be treatable, but can not be cured.
Alzheimer’s disease is the most common cause of dementia, the cause for nearly 50 percent of dementia cases.  Alzheimer’s usually appears in adults from ages 65 years or older and progressively worsens throughout the duration of the following seven to ten years.  This disease provokes dementia by distributing anomalous amounts of protein in the brain which deteriorate or obliterate cells in the cerebral cortex. Medication can be prescribed to slow the process of dementia within Alzheimer’s disease. However, a cure has not been found. 
Not all cases of Parkinson’s disease constitute dementia. Although, if a case of dementia within Parkinson’s is determined, the dementia remains progressive, meaning the disorder evolves over time. Symptoms of Parkinson’s that lead to a diagnosis of dementia include the repercussions of Parkinson's in subcortical parts of the brain that control reasoning, judgement, and memory. In other words, the brain cells in the cerebral cortex are damaged. Other symptoms of Parkinson’s disease entail limb stiffness, problems with speech, and tremors. Medication can be prescribed that slows the process of dementia within Parkinson’s. However, a cure has not been found. 
A disease that seems to be a combination of Alzheimer’s disease and Parkinson’s disease is Lewy-body disease. Similar to Alzheimer’s disease, Lewy-body disease deposits abnormal amounts of protein in the brain, however, the process is catalyzed by distinct proteins called lewy-bodies. Lewy-body disease shares two symptoms with Parkinson’s disease: muscle rigidity and trouble with speech. Dementia classifies as a side-effect of Parkinson’s disease as the illness hinders analytical thinking, the ability to focus, speech, and memory. Medication can be prescribed that slows the process of dementia within Parkinson’s. However, a cure has not been found or administered. 
Huntington’s disease is a hereditary disease that causes damage to the brain cells which regulate motor skills, the ability to think , behavior, irritability, anxiety, depression, muscle stiffness, weakness, and clumsiness.  Huntington’s disease is usually diagnosed in patients who are in their 30’s to 40’s.  Dementia is not always a leading factor in Huntington’s disease, and if it appears, commonly appears late in the disease.  Medication can be prescribed that slows the process of dementia within Huntington’s. However, a cure has not been found.
Creutzfeldt-jakob’s disease is a rare diagnosis. This disease more commonly occurs in young adults,  however, it is not uncommon for it to appear in older adults as well.  This particular ailment is evoked by endemic agents, named prions, which kill brain cells that affect behavior, memory,  judgement, thinking, and sight.  The damage received by the brain cells causes dementia within Creutzfeldt-jakob’s disease patients. Medication can be prescribed that slows the process of dementia within Creutzfeldt-jakob’s. However, a cure has not been found or administered.
Vascular dementia is the second most common cause of dementia following Alzheimer’s disease averaging about 40 percent of diagnosed dementia cases. Vascular dementia is caused by atherosclerosis (a technical word meaning the hardening of arteries) in the brain.  In result, patients are at high risk for strokes, heart attacks, high blood pressure, buildup and debris clogging the heart valve, infection of the heart valve, and a serious lack of oxygen to the brain. It is that last part that truly influences the damaging effects of traditional dementia. By not supplying enough oxygen to brain cells, they begin to die.  Medication can be prescribed that slows the process of vascular dementia. However, a cure has not been found.
Chronic Traumatic Encephalopathy
Chronic traumatic encephalopathy, otherwise termed as dementia pugilistica or boxer’s dementia, is induced by repetitive head injuries. This disorder in particular is associated with the sport boxing, because of the number of athletes who suffered from it after years in the ring. Similar to Huntington’s disease, symptoms of dementia may not appear until years after the damage had been received. Many hindrances partner alongside dementia pugilistica such as memory loss, loss of coordination, speech impairments, muscle stiffness and tremors.  Medication can be prescribed that slows the process of dementia within chronic traumatic encephalopathy. However, a cure has not been found.
Disorders in hormone-secreting glands or hormone regulating organs can lead to a hormone imbalance in the body, causing dementia. However, this can be reversed by administering medication to help balance the glands or organs. 
Liver, pancreas, and kidney, and thyroid disease lead to dementia by first causing delirium, a disorder, of which dementia is a symptom.  Also a lack of sugar in the bloodstream, lack of or too much sodium or calcium in the body can cause short-term dementia. All of the above listed causes of dementia can be reversed by medicine administration or surgery. 
Nutrient deficiencies that could lead to temporary dementia include: dehydration, lack of vitamin B, negative reaction to medication, and subdural hematomas (bleeding between the brain's surface the skull). Dementia caused by these problems can be reversed through hydration, intake of vitamin B, hospitalization, and surgery. 
Brain tumors can cause dementia by many possible routes. The tumor may press against an important part of the brain structure that controls hormone secretion, or simply cause direct brain cell damage from pressure. Both of these reasons that dementia may be caused by a brain tumor can be reversed by surgically removing the tumor or the prescribing medicine to the patient. 
Hypoxia, or anoxia, is simply a lack of oxygen being circulated to the brain. Common cases of hypoxia are caused by heart and lung diseases.  This deficiency can cause short-term dementia until the supply of oxygen is improved or renewed. 
Continuous exposure to solvents, metal dust, or fumes without the correct protective gear, and pesticides  may cause dementia due to brain cell damage. Treating or avoiding the exposure will reverse the symptoms of dementia. 
Sleeping pills, tranquilizers, and drugs that cause sedation, dry mouth, and constipation can lead to dementia. Also, recreational abuse of cocaine or heroin can cause dementia by affecting the blood circulation to the brain. The reduction or withdrawal from these drugs will reverse the symptoms of dementia. 
Any kind of inflammation of the brain usually causes dementia. Examples of this would be kinds of infections that affect the brain structure such as meningitis, encephalitis, HIV, AIDS, and syphilis, lyme disease, leukemia, and multiple sclerosis.The treatment of these diseases through medication, or other means, will reverse the dementia caused by them. 
The recreational abuse of alcohol can lead to dementia by brain cell damage. The reduction or withdrawal from alcohol can reverse the effects of dementia. 
Head injuries sustained from car wrecks, falls, or wounds and assaults can damage the victim's brain cells leading to dementia. The effects of dementia can be reversed by the treatment and monitoring of the injuries. 
The symptoms of dementia differentiate depending on the individual, cause, and type of dementia. Most dementia patients display the symptoms listed below but the strength of them vary. 
Early onset symptoms of dementia include difficulty recalling words, forgetting names, appointments, where objects are placed, and whether or not the individual has already or yet to perform an action. Also seen are sociable personality changes, uncommon behavior, mood swing, lack of orientation (the time and place),  and difficulty in planning and organization. 
As the disease progresses, loss of everyday functions (the ability to get dressed, going to the bathroom unassisted, and eating), experience interrupted sleep, the inability to learn new things, hallucinations, and poor focus. Also, the increase of previous symptoms such as disorientation and mood swings occur. The individual may begin to believe they have experienced events that never actually occurred. 
In the last stages of dementia more harsh conditions are observed. As well as the worsening of all previous symptoms, complete dependence on others is initiated, loss of long-term memory, dehydration, malnutrition, the loss of bladder control, infections,  paranoia, , and frequent injuries from falling or muscle stiffness  take place.
Physical testing of dementia include a doctor/patient interview. The physician will ask questions about when the symptoms began, past and present personal medical issues, past and present family-related medical issues, if the individual is on any medications, their work, their travel, their habits and lifestyle, and any present or past illnesses as well as the person's mood and relative stress level to diagnose dementia. 
Mental testing includes the observation of the individual's cognitive abilities such as memory, focus, orientation, logic, and the ability to solve problems, follow instructions, perform everyday tasks  as well as the testing of balance and language skills  to see if the functions that dementia affects have been altered.
Many blood tests can be taken to see if the individual may have any diseases or disorders of which dementia is a side effect or to rule out a disease that may have similar symptoms to dementia. Some of these test include a complete blood cell count (EBC), vitamin B level check, syphilis test, HIV test, arterial blood gases test (to check for hypoxia), thyroid function test,  AST or ALT (to check liver function), erythrocyte sedimentation rate test (to check for inflammation), antinuclear antibodies test (to check for autoimmune diseases), and a heavy metal blood test (to check for metal poisoning or exposure), blood glucose test (to check for diabetes), a cerebrospinal fluid analysis (spinal tap) (to check for brain infections. 
Two things that can cause dementia that can be determined from urine testing is kidney disease and metabolic disorders. 
Brain Image Studies Tests
Four brain image studies tests are usually administered to determine why parts of the brain are being affected by symptoms of dementia. These four tests are a CT scan (to check for brain tumors), a MRI (to check for brain tumors), SPECT images (to check for hypoxia), and an EEG (to record electrical activity in the cerebral cortex to check for any brain signal interruption). 
The physician may have the patient consult a psychiatrist (to check for psychiatric disorders). 
Treatment of dementia is always dependent upon its cause. The most important form of dementia treatment is supportive daily care, usually by the family. Other forms of treatment relate to the specific cause.  For example, surgery to remove tumors or infections from the brain, medicine to treat an illness with side effects including dementia, or the withdrawal from harmful substances such as recreational drug and alcohol abuse, and behavioral therapy for psychological disorders.  Prescribed medicine, like cholinesterase inhibitors, to reduce the effects of dementia such as Aricept, Exelon, Razadyne, and Namenda, enhance transmitter signals that control memory, logic, and learning.
There are many different ways to prevent the onsets of dementia. The lowering of cholesterol, the lowering of blood pressure, monitoring diabetes, and keeping up with common vaccinations are all positive steps in the right direction.  Some everyday ways to prevent dementia are a balanced diet, regular exercise, no smoking, moderation of alcohol intake, refraining from smoking, refraining from any kind of substance abuse, practicing safe sex, and wearing the appropriate protective gear for daily situations (seat belt, correct sports gear for physical activities, etc.).  Also, after consulting with a doctor, taking aspirin is effective in reducing the risk of strokes, which could cause dementia.  There are however, more fun ways to prevent dementia. Mind stimulating activities such as puzzles, word games, painting, drawing, trivia, or playing an instrument help cognitive functions to stay active as well as social activities like traveling, watching movies, and viewing exhibits are also helpful in maintaining cognitive health. 
- Alzheimer's disease
- Asperger syndrome
- Attention deficit hyperactivity disorder
- Bipolar disorder
- Bovine spongiform encephalopathy
- Bulimia nervosa
- Childhood amnesia
- Dissociative identity disorder
- Obsessive compulsive disorder
- Paranoid personality disorder
- Paranoid schizophrenia
- Personality disorder
- Posttraumatic stress disorder
- Walking corpse syndrome
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