3. Muscle pain
Muscle pain in Legionaries disease is caused by an immune response and increased body temperature. In the beginning, muscles are painful due to damaged muscle fibers. As the process of regeneration starts, patients report stiffness which sometimes cause difficulties moving.
The process of regeneration may take 4 to 6 to kick in and is usually one of the first signs of recovery. This time-frame does not apply to immunocompromised patients who usually suffer a complicated form of the disease which lasts longer.