Most of us are at least somewhat familiar with Alzheimer’s disease. It is the most common type of dementia. But it is only one of many forms of dementia.

Like Alzheimer’s disease, most types of dementia have a devastating impact on memory and mental capabilities. And, also like Alzheimer’s, the damage caused by these diseases is irreversible.

The most frequently diagnosed forms of dementia include:

1. Alzheimer’s disease: Alzheimer’s is by far the most widespread form of all dementias. It accounts for as much as 80% of all cases. While researchers still aren’t certain what causes Alzheimer’s, there is growing research to show it may be linked to conditions such as diabetes and high cholesterol. Genetics also play a role with some types of the disease.

2. Vascular Dementia: Second only to Alzheimer’s, vascular dementia is another commonly diagnosed form of dementia. It occurs when there is an interruption in the blood flow to the brain often caused by a stroke, heart disease or diabetes. As the rates of obesity and diabetes in this country continue to climb, this type of dementia will likely rise.

3. Lewy-Body Disease (LBD): This type of dementia occurs as the result of protein deposits that build up on nerve cells in the brain stem. It results in muscle rigidity, behavioral issues, cognitive loss, hallucinations and tremors.

4. Frontotemporal Dementia: Another tough form of dementia, Frontotemporal impacts the front and side portions of the brain. The result can be impaired speech, memory impairment, and behavioral problems. It often causes a loss of inhibition that is difficult for family caregivers to control.

5. Parkinson’s Dementia: When Parkinson’s disease (PD) progresses, it can lead to dementia. This causes memory loss and other typical dementia symptoms in addition to the already tough symptoms of PD.

6. Huntington’s Disease: This type of dementia has a strong genetic link in families. It results from a gene defect. Symptoms include poor judgment, cognitive loss, speech difficulties, and depression. Many older adults with Huntington’s also develop mood swings.

7. Mixed Dementia: Finally, we come to mixed dementia. This occurs when a senior has two different types of dementia. Many researchers believe a significant portion of people who live with dementia actually suffer from more than one type. The most common combination is Alzheimer’s disease and vascular dementia.