As with fibromyalgia, there are no diagnostic laboratory or imaging tests available for myofascial pain syndrome (MPS), and many physicians are not adequately informed or educated about it.

Medical history and physical examination are the keys for making the diagnosis. The medical history should include a detailed pain history, including when and how the pain began, the exact location of pain, which treatment therapies have been attempted (and their results) as well as any incidences of trauma, repetitive motion injuries or illness present.

When performing the physical examination, the physician will focus on the areas of pain and discomfort and observe the patient’s movements and posture. To enable the identification of the characteristic trigger points (TrPs), the patient should be as relaxed as possible. The physician will feel the muscles by palpation (applying pressure with one to three fingers and the thumb) to locate the TrPs, which consist of tender, hard (or ropy) knots or nodules surrounded by what feels like normal muscle tissue. Once a TrP has been located, the local twitch response may be elicited as muscle or skin twitching.

A physician will look for the four types of TrPs associated with MPS:

• Active TrPs. Areas of extreme tenderness located in skeletal muscles resulting in local or regional chronic pain.
  
  
• Latent TrPs. Dormant (inactive) areas in the muscles that can potentially become painful when activated by factors, such as palpation, trauma, stress or illness.
  
  
• Secondary TrPs. Hyper-irritable areas in the muscles, which become active due to the presence of other TrPs and muscular overload in other muscles.
  
  
• Satellite myofascial points. Hypersensitive spots in the muscles that become active because they are located within the region of other TrPs.

Physicians may perform additional diagnostic tests to help exclude certain other conditions with similar symptoms or identify conditions exacerbating the symptoms. These can include:

• Blood tests such as:
  
• • Complete blood count. Measures the number of red blood cells, white blood cells and platelets in a patient’s blood as well as the amount of hemoglobin (a substance that carries oxygen throughout the body) in the red blood cells and a number of other factors. Some rheumatic conditions or certain drugs used in the treatment of arthritis are associated with low counts of white blood cells (leukopenia), red blood cells (anemia) or platelets (thrombocytopenia).
    
    
  • Enzyme test. A group of blood and/or urine tests that measure enzymes (proteins required for chemical reactions to take place in cells) levels in the blood. These tests assess how well the body’s systems are functioning and whether any tissue damage has occurred.
    
    
  • Sedimentation rate. Can indicate the presence of inflammation typical of many forms of arthritis (e.g., rheumatoid arthritis, ankylosing spondylitis) and many of the connective tissue diseases (e.g., lupus).
    
    
  • Testing for levels of vitamins C, B1, B6, B12 and folic acid in the blood. Deficiencies of these vitamins have been associated with MPS.
    
    
• Other tests, such as:
  
• • Ultrasound. An imaging technique that uses high-frequency sound waves to obtain images inside the body. It is more effective than an x-ray in displaying soft tissue masses and can show tears in ligaments, muscles, tendons and other soft tissue masses in the back that may be responsible for the pain.
    
    
  • Thermography. A safe and noninvasive technique that uses infrared or liquid crystal light recorders to take thousands of pictures of the body. The information is then converted into electrical signals, which results in a computer-generated two-dimensional picture of abnormally cold or hot areas indicated by color or shades of black and white. Thermography may be used to detect vascular disease of the head and neck, soft tissue injury, various neuromuscular disorders, and the presence or absence of nerve root compression.
    
    
  • Electromyography (EMG). A test that measures the electrical activity generated by active muscles to assess nerve function and diagnose causes of neuromuscular problems.

Physicians may also require formal or informal assessments to detect potential mood and sleep disturbances, such as depression, anxiety and insomnia, which are common related symptoms of MPS.