Our bones are continually being remodeled in a two-step process: the “breakdown” of bone (resorption) and the replacement of the removed bone (formation). In osteoporosis, the bones are weakened because the breakdown occurs faster than the rebuilding. When bone is resorbed, fragments of the bone collagen are released into the bloodstream. One of these fragments is called “C-telopeptide.” This test helps assess the loss of bone mass in cases of osteoporosis or other bone diseases such as Paget’s disease.
C-reactive protein (CRP) is a protein produced by the liver. Normally, you have low levels of C-reactive protein in your blood. Your liver releases more CRP into your bloodstream if you have inflammation. High levels of CRP indicate you have a serious health condition that's causing the inflammation.
Inflammation is your immune system's response to injury, infection, and certain cancers. It can also result from blood or immune system disorders. An erythrocyte sedimentation rate (ESR) is a blood test that identifies inflammation in your body.
Your muscle tissue and red blood cells produce lactic acid, which rises in level as oxygen decreases. A lactic acid test can help diagnose lactic acidosis, find out if enough oxygen is reaching the body's tissues, and diagnose sepsis, a life-threatening reaction to bacterial infection.
During serious bacterial infection, the cells in many parts of your body release procalcitonin into your bloodstream. A high procalcitonin level in your blood may indicate a serious infection or sepsis. This test helps diagnose or rule out bacterial infection and/or sepsis, determining how serious the infection may be and helping with treatment decisions and monitoring treatment effectiveness.
Rheumatoid factors are proteins that sometimes mistakenly attack healthy cells and tissues in your body. Not everyone has rheumatoid factors in their blood. If you have high levels of rheumatoid factors, you may have rheumatoid arthritis. This disease can damage your joints and cause pain, swelling, and stiffness. It is a chronic (long-lasting) condition that can affect your organs and cause other symptoms.