Polymyalgia rheumatica, often abbreviated to PMR, is a syndrome causing progressive stiffness in certain joints. It is primarily observed in individuals over 60 years of age, and mainly affects the pectoral girdle, or in other words, the shoulders and cervical vertebra of the spine, and the pelvis, particularly affecting the hips. The stiffness is painful and progressively worsens. The exact cause for this syndrome is as yet unknown, but without treatment it can progress in around 30% of cases to an associated giant-cell arteritis, where the arteries become inflamed. Treatment methods are corticosteroid-based.