Complex Regional Pain Syndrome (CRPS): A chronic condition causing severe pain, swelling, and changes in skin color and temperature, typically affecting an extremity.

Celiac disease is an autoimmune disorder where the ingestion of gluten causes damage to the small intestine.

Fibromyalgia: a chronic condition characterized by widespread pain, fatigue, and tenderness in the body.

Pernicious anemia is a condition where the body does not absorb enough vitamin B12, resulting in fatigue and weakness.

Sjögren's syndrome is a chronic autoimmune disorder that affects the body's moisture-producing glands, causing dry eyes and mouth.