A hair mineral analysis test reflects the storage levels of minerals rather than just what is being transported in the blood. The body transports metals in the blood, but does not keep them there. Metals are stored by the body where they cause the least amount of damage, in the tissues. Blood tests reveal what is circulating in the body; hair tests reveal what is stored in the body. To demonstrate:
- Calcium loss from the body can become so advanced that severe osteoporosis can develop without any appreciable changes noted in the calcium levels in a blood test as blood would pull calcium from the bones to always appear perfect.
- Symptoms of iron deficiency can be present long before low iron levels can be detected in the blood.
- 30 to 40 days following an acute exposure of metals such as lead, elevated blood levels of lead may be undetectable. This is due to the body removing the lead from the blood as a protective measure and depositing the metal into such tissues as the liver, bones, teeth and hair. 
Hair tissue mineral analysis is screening test to measure the levels of 21 or more minerals in the hair tissue. Hair is also a storage tissue and a tissue that the body uses for excreting excessive amounts of toxic metals and other substances such as illegal drugs to help rid them from the body. Therefore it is an excellent place to measure these items. Hair provides a unique, biopsy type of reading of metabolic activity.
Blood tests do not provide the same information as a properly performed hair analysis. Hair analysis measures a different body compartment. Minerals are shifted from the tissues to maintain blood levels. This means that deficiencies or excesses often show up earlier in the hair than the blood.
Few doctors understand both types of tests well enough to interpret the hair and the blood tests correctly to understand how they relate to each other. A few of the major differences between hair testing and other common tests include:
- The hair measures a different body compartment than the blood or urine.Each has its own metabolism.
- The blood is maintained at the expense of tissues such as the hair.This means the hair will change first, often years before the blood. The blood is far more buffered. It has to be because it touches every cell. Large variations in mineral levels here would be fatal. This is not the case with the hair.
- The hair is a storage organ and, to some degree, an excretory tissue. The blood is a transport medium.
- Blood, urine and saliva provide short-term or even instantaneous readings, whereas a hair test provides a 3-month average or a longer-term reading.
- Blood sample test results vary depending on the time of day and food/drink consumed.
- Homeostatic mechanisms at work in the blood such as buffering of pH and osmotic balance are extremely different from homeostatic mechanisms at work in the tissues and at the cellular level in the hair.
Toxic metals rarely remain in the blood for long, but often deposit in the hair where they can be measured. Hair analysis gives a long‑term reading that is unaffected by recent meals, activities such as exercise, or emotional states. These and other differences make blood and tissue testing very different, with each providing valuable information. 
Judge Brian of the Federal District Court at Alexandria, Virginia, tried a case challenging the accuracy and reliability of hair analysis. In January, 1985 he determined that hair analysis is a reliable indicator of essential and toxic elements and minerals contained in the body as a whole. Given the evidence that was presented concerning multielemental spectral hair analysis, Judge Brian concluded that the procedure was a “useful guide in the hands of a health care professional.” He further added that when “used along with other relevant information in the treatment, the results of this procedure can help in prescribing nutritional supplements and in the caring for a specific patient where a chemical imbalance in the body is suspect.”
Before hair analysis, medical practitioners who were interested in the concentration of trace elements in the body had to rely on urine or serum sampling. Unfortunately, these tests have been shown to be inaccurate because they do not measure the intracellular concentration of minerals. 
Read on: The next blog entry is: “Can I just rest? Or eat better?”