What is the difference between and Dementia, Alzheimer's and Parkinson's

Parkinson's disease is a different brain disorder that primarily affects movement. It usually begins with symptoms like tremors (shaking), muscle stiffness, slowed movements, and difficulty with balance and coordination. Parkinson's is caused by the loss of nerve cells that produce dopamine, a chemical important for controlling movement. Unlike Alzheimer's, Parkinson's often starts earlier, around age 50 to 65. While Parkinson's mainly affects movement, some people develop dementia later, known as Parkinson's disease dementia. This dementia affects problem-solving, speed of thinking, memory retrieval, and mood. It also often includes hallucinations and delusions, which are less common in Alzheimer's dementia.