Scabies is a contagious skin infestation caused by the microscopic mite Sarcoptes scabiei. These mites burrow into the top layer of the skin, where they lay eggs and cause intense itching.

Cardiac arrhythmias are abnormalities in the heart's rhythm, which can manifest as irregular heartbeats.

Dementia is a general term for a decline in mental ability that interferes with daily life. It primarily affects memory, thinking, language, and judgment, and is most commonly seen in older adults. Alzheimer's disease is the most common form of dementia.