7. Other possible causes of dementia
Rarely, certain conditions cause dementia that is partially or completely reversible. These include:
- A brain tumor
- Normal pressure hydrocephalus (an irregular accumulation of cerebrospinal fluid in the brain). This type of hydrocephalus usually affects people over 65.
- A head injury that causes hydrocephalus or a subdural hematoma, which is an accumulation of blood underneath the brain's covering
- A thyroid or other metabolic or endocrine disorder
How they're diagnosed and treated: Tumors, hydrocephalus, and subdural hematomas can be identified through a medical history and a brain scan. Thyroid or other endocrine or metabolic disorders can be identified through laboratory tests of the blood and urine. About 1 in 10 dementia cases have an unknown cause.

