Dementia is a decline in mental function that may interfere with the ability to perform daily tasks. Dementia is a common condition, especially among older people. However, dementia should not be considered a normal part of aging.

There are many different types and causes of dementia. According to the National Institutes of Health, Alzheimer's disease is the most common cause of dementia, followed by vascular dementia. Vascular dementia is caused by a lack of blood to the brain, often following a stroke. Other types of dementia include:

• Lewy body dementia
• Frontotemporal dementia
• Corticobasal degeneration
• Huntington’s disease
• Creutzfeldt-Jakob disease (CJD)

The biggest risk factor for dementia is age. People over the age of 85 are more likely to experience the condition, although some forms of dementia occur in people under the age of 50. Some individuals are genetically more susceptible to develop certain forms of dementia, such as Alzheimer's and Huntington’s diseases. Additionally, several factors can cause temporary or permanent dementia, such as:

• Brain injuries (including damage caused by stroke)
• Malnutrition
• Infections
• Reaction to medication
• Poisoning
• Brain tumor or lesion

Memory loss is one of the most characteristic symptoms of dementia, along with language difficulties, poor judgment and personality changes. People who begin to display signs and symptoms of dementia may be referred to a physician who will likely conduct tests to assess the cause and extent of dementia. Some causes of dementia are often treatable and reversible (e.g., dementia due to malnutrition). However, sometimes dementia reflects permanent damage to the brain, or can grow progressively worse over time.

Dementia can affect many aspects of the patient’s life. As the disease progresses, the patient may not be able to drive or live independently. This can be frustrating for both the patient and caregivers. In some cases, professional round-the-clock assistance is required to care for the patient.