Dementia is the progressive deterioration and impairment of memory, reasoning, and other cognitive functions resulting from an illness or condition. Dementia can affect a person's ability to carry out daily activities. For example, the person may forget where they live or think they have already done their activities but never did. Dementia can also make older people incontinent and unable to control their urinary system. Many people think of dementia as an illness. Dementia is not an illness. However, this can lead to an illness or condition. Dementia is more common in older people. It is normal for people to forget things, but to some extent it becomes a critical problem. Depression also plays a role in the effects of dementia. Studies have been made to believe that the biological mechanisms of dementia-related depression are "interactions with vascular diseases, changes in glucocorticoid levels which can lead to hippocampal atrophy, accumulation of amyloid plaques -β, inflammatory processes and a lack of nerve growth factors” (Heser et al., 2013). Dementia is caused by plaques and neurofibrillary tangles. This may also be known as Alzheimer's disease. Dementia is the leading cause of Alzheimer's disease in older adults. For all cases of dementia, 60 to 80 percent of people with dementia will have Alzheimer's disease. The disease has 3 different stages: early stage, intermediate stage and advanced stage. Each of these stages presents a variety of symptoms that affect the person's memory problems (Wieregna, Bondi, 2011). Parkinson's disease and Huntington's disease are also linked to dementia. These diseases can lead to impairments, which can pose a challenge middle of paper around the world. There is no cure for dementia and other dementia-related illnesses. Dementia is the main cause of Alzheimer's disease. Alzheimer's disease is also the most common disease associated with dementia (Wieregna, Bondi, 2011). Dementia can affect the patient and their family in many emotional ways. Knowing that their loved one will suffer from numerous mental disabilities and will likely not be able to recall certain memories can be tragic. Dementia can also affect families financially. The cost to a patient increases significantly each year due to the increase in population (Hurd, 2013). Dementia can also lead to Parkinson's disease and Huntington's disease, which can affect the patient's mobility (Quinn, Busse, Dal Bello-Hass, 2013). Dementia remains one of the most diagnosed diseases worldwide. Without a cure, many more people will be affected.