1. Introduction: Seasonal Challenges in Thyroid Health

 

During the colder months, subtle changes in energy, metabolism, and overall well-being are common. Patients may report fatigue, weight fluctuations, increased sensitivity to cold, or low vitality. While these symptoms can have multiple causes, they may also indicate underlying thyroid dysfunction, particularly hypothyroidism.

 

Seasonal factors such as reduced physical activity, shorter daylight hours, and dietary changes, can make these symptoms more noticeable. Timely and accurate assessment of thyroid function provides essential guidance for clinical decisions, supporting appropriate therapy adjustments and long-term health management.

 

2. Key Thyroid Markers and Clinical Relevance

 

Monitoring multiple thyroid markers provides a comprehensive view of thyroid health. 

The diagram shows the main hormones and feedback mechanisms involved in thyroid function.

Essential Thyroid Markers

 

Marker	Clinical Role & Significance
TSH (Thyroid Stimulating Hormone)	First-line screening for thyroid dysfunction; sensitive indicator regulated by hypothalamic-pituitary-thyroid feedback
TT4 (Thyroid Stimulating Hormone)	Main circulating thyroid hormone; evaluates hyperthyroidism, primary/secondary hypothyroidism, and TSH-suppressive therapy
TT3 (Total Triiodothyronine)	Reflects thyroid impact on peripheral tissues; useful for early hyperthyroidism detection and monitoring relapses
FT3 (Free Triiodothyronine)	Biologically active hormone; unaffected by TBG; sensitive for hyperthyroidism, including T3-dominant cases
FT4(Free Thyroxine)	Free, active thyroxine; early marker for hypothyroidism and hyperthyroidism; preferred for assessing thyroid insufficiency

 

Assessing all five markers ensures early detection of subclinical hypothyroidism, hyperthyroidism, or altered metabolic status, which is particularly important during winter when symptoms may be masked or attributed to seasonal factors.

 

Routine Thyroid Function Panels

 

Panel	Tested Markers	Target Population	Clinical Significance
TSH only	TSH	All routine check-up populations	Primary screening for thyroid dysfunction
3-Marker Panel	TSH, FT4, FT3	All routine check-up populations	Measures active thyroid hormones; reflects true thyroid function; unaffected by TBG variations
5-Marker Panel	TSH, FT4, FT3, TT4, TT3	Check-ups, follow-ups, or medication monitoring	For patients with confirmed thyroid disorders or under treatment; provides comprehensive evaluation of therapy effectiveness and side effects

 

 

Recommended test population

 

 

3.  Poclight Thyroid Test Kit Advantage

 

Poclight’s dry CLIA platform offers significant benefits for thyroid diagnostics:

 

1)  Low Sample Volume & Rapid Results

Only 50 μL of serum or plasma needed, with 5-10 minute turnaround, ideal for fast clinical decisions.

 

Item	Sample type	Assay duration	Sample volume	Cut-Off value	Measuring range
FT4	Serum/ Plasma	5min	50 μL	12~22 pmol/L	0.5~100 pmol/L
FT3		5min	50 μL	3.1~6.8 pmol/L	0.6~50 pmol/L
TT4		5min	50 μL	66~181 nmol/L	5.4~320 nmol/L
TT3		5min	50 μL	1.3~3.1 nmol/L	0.3~10 nmol/L
TSH		10min	50 μL	0.27~4.20 μIU/mL	0.005~100 μIU/mL

 

2)  Freeze-dried reagents: no cold chain, 18 months shelf life, 2-30 degree storage and transport.

 

3)  High accuracy and excellent precision - CV < 5%

 

 

4)  Applicable with the C5000 POC CLIA Analyzer: 3-Step Operation, Maintenance-Free

 

 

 

Contact us to learn about local distributors and pricing options for Poclight D-dimer solutions.