What is dementia? Dementia occurs when brain function is lost. Thought processes, judgment, behavior, language ability, and memory can be affected. Dementia can occur with a variety of different conditions. It is most common after the age of 60, although it can occur at earlier ages. The progression of dementia can be halted or reversed in some cases, particularly when the dementia is due to medications, alcohol abuse, hormonal or chemical imbalances, vitamin deficiency, depression, infection, heart or lung disease, normal pressure hydrocephalus (fluid collection in the brain), or brain tumors. The most common types of dementia, however, are progressive. Alzheimer’s disease, a degenerative condition, is the most common cause of dementia. Other degenerative causes of dementia include Lewy body dementia, Parkinson’s disease, and Huntington’s disease. Progressive dementia can also be caused by vascular disorders such as multi-infarct dementia and by infections such as HIV and Creutzfeldt-Jakob disease. Treatment of dementia depends upon the underlying cause(s). For reversible causes, approaches such as changing medications, correcting chemical imbalances or deficiencies, or treating medical conditions may be helpful. Some medications are available to help slow the degenerative changes seen with Alzheimer’s disease, and others are available to help control the behavioral changes that may occur. Dementia is usually a progressive disease, but in some circumstances it can be managed or even reversed. Seek prompt medical care if you notice difficulty with memory, thinking, talking, comprehension, writing or reading; increasing confusion; inability to care for yourself and your daily needs; changes in mood, personality or behavior; or other symptoms that concern you.