TL;DR: PMR mainly affects adults over 50, is more common in women, and is seen most in people with Northern European backgrounds. Rates vary by country — from about 13 to 113 cases per 100,000 people age ≥50 each year —and the chance of also having GCA is about 10–20%.
Age
- PMR is rare before 50.
- Risk climbs through the 60s and 70s.
Age is the strongest known risk factor.
Sex
Women are affected 2–3 times as often as men in many studies.
Ancestry and geography
PMR occurs worldwide, but studies show higher rates in Northern Europe and people of Northern European ancestry. Reviews also describe a north–south gradient in Europe (higher in the north, lower in the south).
How common is PMR?
Epidemiology varies by location and how cases are counted. Recent summaries report:
- Annual incidence ranging from about 13 to 113 per 100,000 people aged ≥50, depending on the country.
- U.S. and U.K. estimates fall in the middle of that range and confirm that PMR is common in primary care for older adults.
PMR and GCA: how often together?
- About 10–20% of people with PMR develop giant cell arteritis (GCA) at some point.
- About 40–50% of people with GCA have PMR symptoms.
These overlaps matter because GCA can threaten vision and needs same-day care.
Do seasons matter?
Some older reports suggested possible seasonal peaks, but newer studies are mixed and no firm seasonal pattern is accepted today. The takeaway: stay alert to symptoms year-round.
Other things researchers are studying
Scientists are exploring genes, aging of the immune system, and possible environmental triggers (like infections) to explain why PMR starts in some people and not others. The most consistent signal so far is the role of IL-6 (Interleukin-6) — a key inflammation messenger that’s often high during active PMR.
What this means for you
- If you’re over 50 with new shoulder/hip stiffness that’s worst in the morning, talk with your clinician.
- If you already have PMR, know your GCA red flags (new headache, scalp tenderness, jaw pain while chewing, any vision change) and seek urgent care if they appear.
