Diagnosing polymyalgia rheumatica (PMR) can often be quite a lengthy process involving several different tests.

This is because it shares many symptoms with more common health conditions such as rheumatoid arthritis, which need to be ruled out first.

There's no specific test for polymyalgia rheumatica, but it's likely that a series of blood tests will be done.

Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are blood tests that can be used to check the levels of inflammation in your body.

If ESR and CRP are normal, it’s unlikely that polymyalgia rheumatica will be diagnosed.

Sometimes, ESR may be normal and CRP may be raised, which is more likely to indicate polymyalgia rheumatica. This is why both tests are usually done at the same time.

As inflammation is a feature of many conditions, high levels do not automatically mean you have polymyalgia rheumatica.

Find out more about these tests:

• Lab Tests Online: erythrocyte sedimentation rate (ESR)
• Lab Tests Online: C-reactive protein (CRP)

Further tests may be needed to help rule out other conditions that cause inflammation. For example, a test for rheumatoid factor and anti-CCP antibodies may be done to rule out rheumatoid arthritis.

Blood tests can also help determine:

• whether you have a blood infection
• how well your organs, such as your kidneys, are working
• if you have an overactive thyroid gland or an underactive thyroid gland – both conditions can cause muscle pain

You may have a urine test to check how well your kidneys are functioning.

X-rays and ultrasound scans may also be used to look at the condition of your bones and joints.

After ruling out other possible causes of your symptoms, a checklist can be used to see if your symptoms match those most commonly associated with polymyalgia rheumatica.

Polymyalgia rheumatica can usually be confidently diagnosed if you meet all of the following criteria:

• you're over 50 years of age
• you have pain in your shoulders or hips
• you have stiffness in the morning that lasts longer than 45 minutes
• your symptoms have lasted for more than 2 weeks
• blood tests show raised levels of inflammation in your body
• your symptoms rapidly improve after treatment with steroids

Read more about treating polymyalgia rheumatica.