How to Interpret Salivary Cortisol Levels

Cortisol is a hormone secreted by the adrenal glands (above your kidneys) and is regulated by another hormone (ACTH) that is secreted by the pituitary gland (below your brain). Cortisol plays a role in breaking down protein, glucose and lipids in your body, regulates the immune system and helps maintain blood pressure. Many internal and external factors, such as temperature, stress, obesity, exercise and trauma, affect cortisol concentrations in your body. Typically, cortisol level peaks about 8 a.m. and declines in the evening, with the lowest level about midnight. Doctors typically order cortisol testing to diagnose Cushing's syndrome or Addison's disease. Because blood collection causes stress in many people (altering cortisol levels), saliva samples often are used.

Things You'll Need

• Salivary cortisol lab report

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Instructions

• 1

  Check your lab report for the collection time (or times) listed for the saliva samples used for cortisol testing. Generally, morning and evening samples are collected to see if cortisol secretion is following the diurnal variation it should follow (peaks in the morning and declines in the evening.)

• 2

  Read the cortisol results the lab obtained from testing you saliva sample or samples. Depending on the lab performing the test, salivary cortisol could be measured in nanograms (one billionth of a gram) per milliliter, nanomoles (one billionth of a mole-a measure of molecular weight) per liter or another unit. Compare the value listed for your cortisol level with the normal ranges listed by the performing lab. Cortisol ranges vary with sample collection time, units used and other factors, so it is important that you compare your result with the normal range the testing lab provided for you in the report.

• 3

  Discuss abnormal cortisol results with your doctor. If initial salivary cortisol testing shows higher or lower than normal results, additional testing is needed to discover the cause. If your morning cortisol level is normal while the evening cortisol is high, you have excess cortisol secretion. If the lab measures low cortisol levels in the morning, you have insufficient cortisol secretion.

• 4

  Inform your doctor of any medications you are taking, if you are experiencing emotional or physical stress or if you have any underlying illness. All of these factors could temporarily elevate your cortisol levels. Also inform your doctor if you follow an unusual work and sleep schedule. If you work the night shift, your cortisol secretion follows a different pattern because you are awake at night and asleep during the day.