Alzheimer's disease is the most common type of dementia, affecting an estimated 850,000 people in the UK.
Our Health A-Z contains more information on Alzheimer's disease.
Severe head injuries require immediate medical attention because there's a risk of serious brain damage.
Our Health A-Z contains more information on Major head injury.
Important: If you have these symptoms, they may be unrelated to any of these conditions listed. If you are concerned about your symptoms then you should see a doctor.