Autoimmune diseases are conditions in which the body's immune system attacks its own healthy cells and tissues. Alzheimer's disease, on the other hand, is a neurodegenerative disorder that is not considered an autoimmune disease.

Explanation:

Autoimmune diseases are caused by a malfunction of the immune system, which mistakes the body's own tissues as foreign invaders and attacks them. This can lead to inflammation, damage, and dysfunction in various organs and tissues. Examples of autoimmune diseases include:

- Rheumatoid arthritis: a chronic inflammatory disorder that affects the joints, causing pain, stiffness, and swelling.
- Psoriasis: a skin condition characterized by red, scaly patches that can be itchy or painful.
- Vitiligo: a condition in which the skin loses its pigmentation, resulting in white patches.

Alzheimer's disease, on the other hand, is a progressive brain disorder that affects memory, thinking, and behavior. It is caused by abnormal protein deposits in the brain, which lead to the death of brain cells and the shrinkage of brain tissue. While Alzheimer's disease does involve inflammation in the brain, it is not considered an autoimmune disorder because it is not caused by the immune system attacking the body's own tissues.

In summary, Alzheimer's disease is not an autoimmune disease because it is not caused by the immune system attacking the body's own tissues.