Thyroid Testing & PMBT.
When it comes to the harvesting of a Thyroid Blood Screening Test, make sure you are aware of ALL the interfering factors that can give you a non-representative result for that patient. One of those factors may well be the concurrent use of PBMT in the days peri-harvesting the blood screen.
Photobiomodulation/Class 4 lasers can have impacts on a diseased thyroid gland. Whilst we have been taught to avoid the actual thyroid gland itself as one of the normal rules of laser/PBM therapy; more recent articles now suggest that PBMT does not cause morphological changes on the healthy thyroid gland.
However, in the diseased* thyroid gland, PBM therapy can have an actual beneficial effect. In one study in humans, the use of PBMT caused a reduction in the daily dose of thyroid medication. Given that PBMT targets and modulates inflammation and given so many thyroidal diseases are inflammatory or immune-mediated in nature, it makes sense that PBMT would be of benefit, not of detriment, for many of these presentations.
However, the curve ball is that if your patient is on PBM therapy for any reason; be alert that the therapy could alter serum thyroid levels enough that a marginal hypothyroid case might be masked.
If you do run a thyroid screen test, factor in any interference in your serum blood level result.
*Clarification: Never use the laser anywhere near any neoplastic lesion especially if it is a tumour in the thyroid gland i.e. cats.