A commonly encountered condition of dementia is Alzheimer’s disease. It is common in people older than 65 years, but dementia can also occur in younger patients, usually brought about by genetic causes, stroke, brain infection, exposure to toxins, etc. When brain cells die, memory, cognitive and emotional problems along with personality changes can occur.
Causes of Dementia
• Alzheimer’s disease. It is the most common disease associated with dementia. When compared to all degenerative brain disorders, it is caused due to death to a number of brain cells that lead to decreased neurotransmitter function. Patients with this disease suffer from memory loss along and learning problems. As time passes, their condition can continue to regress due to brain cells dying much faster than they should relative to their age. The condition is incurable, and treatment only aims to provide relief to disease symptoms and to maximize the patient’s comfort.
• Stroke. Obstruction of the cerebral arteries can lead to less blood supply to the brain, or tearing of blood vessels in the brain can cause brain hemorrhaging or pressure on the brain tissues, leading to partial brain death and decreased brain ability. In addition to experiencing weaknesses in the limbs, poor balance and speech difficulty, as time passes, dementia can result. Accordingly, preventable factors include hypertension, diabetes, high cholesterol, stress, smoking and heavy drinking.  
Other causes of dementia include the following:

•  Brain infection, AIDS and syphilis.

•  Thyroid disorders.

•  Vitamin B12 deficiency, which is common in cases with absorption deficiencies.

•  Exposure to toxins or drugs.

•  Hydrocephalus.

•  Brain tumors.

•  Chronic brain impacts and prior history of serious brain injuries.

•  Chronic kidney and liver abnormalities, etc.
Factors Contributing to Dementia

•  Older age. Dementia is more common in older people.

•  Genetics. If a family member has dementia, the patient has greater risk of developing dementia than ordinary people.

•  Chronic diseases such as hypertension, diabetes and chronic liver or kidney disease.

•  Heavy alcohol consumption and smoking.

•  Exposure to toxins from the environment and narcotics.

•  Thyroid disorders or parathyroid disorders.

•  Infection such as AIDS and syphilis.

•  Brain impacts such as from accidents or occupations such as boxing.

•  Nutritional deficiencies such as Vitamin B12 deficiency.

•  Hydrocephalus or brain tumors.