PCOS vs thyroid: how to tell the difference
They share symptoms, so they get confused. But they are different conditions with different labs. Here is how to tell them apart.
Evidence-based · Sources cited · Updated July 2026
PCOS (now officially PMOS) and an underactive thyroid share symptoms, but they are different conditions. TSH points to the thyroid, while testosterone, DHEA-S, AMH, and glucose point to PCOS. Do not guess. Get the blood panel that covers both.
Why they get confused
PCOS and thyroid problems, especially an underactive thyroid, share a lot of surface signs. Irregular periods, weight changes, fatigue, and hair changes all show up in both. That overlap is exactly why the two get mistaken for each other.
They are different conditions
PCOS is driven by high androgens and insulin resistance. Hypothyroidism is simply too little thyroid hormone. This matters for diagnosis, because thyroid disease has to be ruled out before PCOS can be diagnosed. It is part of the standard workup.[1]
The labs that separate them
TSH points to the thyroid. Testosterone, DHEA-S, AMH, and glucose or insulin point to PCOS.[2] One panel can cover both, which is why the blood test is where this question gets settled.
The clues in your symptoms
Clues that lean PCOS: acne and unwanted hair growth, both signs of high androgens. Clues that lean hypothyroid: cold intolerance, constipation, dry skin, and a slow heart rate. You can have both at once. The takeaway is the same either way. Do not guess, get the blood panel that covers both.
Not sure where you stand?
Take the 2-minute PCOS check. Get your likely pattern and the exact labs to ask your doctor for.
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Sources
- [1] 2023 International Evidence-Based Guideline for the Assessment and Management of PCOS. PMC10505534
- [2] Polycystic ovary syndrome, WHO fact sheet. who.int
This article is educational and is not medical advice. Talk to a clinician before starting, stopping, or combining treatments.