A midnight salivary cortisol test offers a non-invasive method for measuring the body’s cortisol levels. This test is typically performed at home, providing a convenient way to assess hormonal function. Its primary purpose is often to screen for conditions like hypercortisolism, such as Cushing’s syndrome, where cortisol levels remain elevated throughout the day and into the night. This specific timing is important because cortisol levels are usually at their lowest around midnight in healthy individuals.
Preparing for Your Test
Accurate results depend on careful preparation. Collect the sample precisely at midnight, or at the time indicated by your healthcare provider or kit instructions. Consistent timing ensures the measurement reflects the body’s natural circadian rhythm for cortisol.
Avoid caffeine, alcohol, or nicotine for 30 to 60 minutes before collection, as these can influence cortisol levels. Refrain from eating or drinking anything other than plain water during this pre-collection period. Acidic foods or drinks can affect the sample’s integrity or pH.
Oral hygiene requires attention prior to collection. Do not brush your teeth, floss, or use mouthwash for 10 to 30 minutes before the designated collection time. These activities can introduce contaminants or alter saliva composition, leading to inaccurate results. Avoid physical activity or stressful situations immediately before collection, as both can spike cortisol levels.
Discuss all medications, supplements, or hormonal therapies with your healthcare provider before the test. Certain substances can interfere with measurements; your doctor can advise on adjustments. Before midnight, ensure your test kit is accessible and you understand its components and instructions.
Step-by-Step Sample Collection
Begin by ensuring proper hygiene. Wash your hands thoroughly with soap and water to prevent sample contamination. Once clean, carefully open the collection tube or vial, avoiding touching the inside of the cap or tube to prevent contamination.
The most common method for collecting saliva is passive drooling. Allow saliva to naturally pool in your mouth without forceful spitting or sucking. Once sufficient saliva accumulates, gently tilt your head and let it flow directly into the collection tube. Avoid chewing gum, eating candy, or sucking on lemons, as these can unnaturally stimulate saliva production and alter the sample.
Continue to let saliva passively flow into the tube until it reaches the indicated fill line. Most collection tubes have a clear mark indicating the minimum volume required for accurate analysis. Too little saliva may prevent lab processing; overfilling can also cause issues. Minimize air bubbles, as excessive bubbling can interfere with sample volume and analysis.
Once saliva reaches the fill line, securely close the tube immediately with its cap. Ensure the cap is twisted on tightly to prevent leakage or contamination during storage and transport. Finally, label the tube clearly with your full name, the exact date, and the precise time of collection, following kit instructions.
Post-Collection and Next Steps
After collecting your sample, immediate and proper storage is crucial to maintain its integrity. Most kits require the sample to be refrigerated or frozen immediately; consult your kit instructions for the recommended temperature. Rapid cooling preserves the cortisol until it can be shipped for analysis.
When preparing the sample for shipment, follow your kit’s packaging guidelines carefully. This often involves placing the sealed tube into an absorbent pouch and an insulated mailer, sometimes with an ice pack to maintain a cool temperature during transit. Proper packaging prevents damage and ensures the sample arrives at the lab in optimal condition. Shipping instructions typically advise sending the sample to the laboratory as soon as possible, often requiring overnight shipping or drop-off the following morning. Timely shipment prevents sample degradation and ensures accurate results.
Once the lab receives your sample, processing times vary, but results are typically available within several days to a couple of weeks. Upon receiving your results, schedule a follow-up appointment with your healthcare provider. They can interpret the findings in the context of your overall health, symptoms, and medical history. This article provides general information and is not a substitute for professional medical advice or diagnosis.