4. Glenn Frey
Frey, best known for being the founding member of The Eagles passed away earlier this year after a long battle with rheumatoid arthritis. The star was first diagnosed in 2000. Unfortunately, the medication the star had been taken to treat his arthritis is ultimately what led to his death as it caused various complications including pneumonia and colitis. Frey passed away at the age of 67, a number of weeks after surgery to fix intestinal problems.