For chronic sleep problems, clinicians often start by examining how the thyroid gland is working and checking iron stores in the body. This overview is based on guidance from a sleep medicine specialist at a major university clinic, presenting practical steps for adults dealing with persistent insomnia or other sleep disturbances.
When insomnia is present, it is reasonable to assess thyroid function with tests such as TSH and free T4, or at least TSH alone. Thyroid health can influence sleep, mood, and energy levels, so understanding whether the gland is contributing to sleep disruption helps tailor treatment. It is also noted that sleep disorders themselves can contribute to iron deficiency, creating a cycle that may worsen symptoms if not addressed.
Serum iron levels can vary widely and are not a reliable standalone diagnostic marker for iron deficiency. This is similar to hemoglobin, which can remain normal even when iron stores are low. A more accurate picture comes from examining ferritin, a marker of iron stores, and soluble transferrin receptor levels, which reflect tissue iron status. Together, these indicators provide a clearer view of iron balance and its potential impact on sleep quality.
There is also caution against spending on some expensive or widely promoted tests for sleep-related neurotransmitters, melatonin, or vitamins. While these factors influence sleep, measuring them in blood often does not yield decisive information for diagnosing insomnia. Neurotransmitter levels in the brain, rather than in the bloodstream, determine their effects on sleep, making blood measurements limited in diagnostic value. Melatonin, for instance, naturally fluctuates throughout the day and is typically present only in trace amounts during waking hours, so a single daytime measurement does not offer meaningful guidance for diagnosis or treatment decisions.
In addition, one expert notes that evaluating vitamin deficiencies such as B12 may be helpful in suspected cases of sleep disturbance. An analysis of methylmalonic acid can help identify B12 deficiency, but results must be interpreted within the clinical context. The doctor weighs the patient’s symptoms, medical history, and overall picture before drawing conclusions, rather than relying on a single test result alone.
Overall, a comprehensive sleep assessment involves a balanced approach. Clinicians consider thyroid function, iron stores, and possible nutritional influences while avoiding reliance on tests with limited diagnostic value. By focusing on clinically meaningful biomarkers and the patient’s reported experience, providers can create a clearer path to improving sleep health. This strategy emphasizes thoughtful testing, patient symptoms, and collaboration between the patient and clinician to determine the most effective steps forward.