You got your bloodwork back. TSH is 6.8. Your family doctor either called to say it's "slightly elevated, we'll monitor it" or — more frustratingly — didn't call at all because it wasn't flagged as urgent. You're exhausted, gaining weight, feeling cold, and searching for answers.
Here's what TSH 6.8 actually means, why there's genuine disagreement in medicine about what to do with it, and — critically — what additional tests determine whether you need treatment. Because TSH alone, at 6.8, does not give you the full picture. But it's enough to know you should not simply accept "let's monitor it" without more information.
What TSH measures — and why 6.8 is significant
TSH stands for thyroid-stimulating hormone. It's produced by your pituitary gland — a small structure at the base of your brain — and its job is to signal your thyroid gland to produce thyroid hormones (T3 and T4). When your thyroid is underperforming, the pituitary gland responds by producing more TSH to try to compensate. So a high TSH generally means your pituitary is working overtime because your thyroid isn't producing enough hormone.
The standard laboratory reference range for TSH in Canada is roughly 0.4 to 4.0 mIU/L, though this varies slightly between labs. A TSH of 6.8 is above this range — meaningfully so. Here's how endocrinologists typically interpret the ranges:
With TSH at 6.8, you're in the subclinical hypothyroidism range. This is where clinical practice varies the most — and where the gap between a GP's response and an endocrinologist's response is most likely to leave you without adequate care.
Why your GP might say "let's monitor it"
Family doctors in Canada are generally taught to treat overt hypothyroidism (TSH above 10) and to monitor subclinical cases. This reflects older clinical guidelines that were cautious about over-treating borderline thyroid dysfunction. The reasoning is that some people have TSH fluctuations that normalize on their own, and unnecessary thyroid medication can cause its own problems — including bone loss and cardiac arrhythmia if doses are too high.
This is not wrong as a general policy. But it can lead to under-treatment of patients who are genuinely symptomatic. A TSH of 6.8 with fatigue, weight gain, cold intolerance, hair changes, brain fog, or low mood is a different clinical picture than TSH 6.8 with no symptoms at all. The number alone does not tell the whole story — but neither does "let's check again in 6 months."
What an endocrinologist looks at beyond TSH
The single most important thing to understand is this: TSH is a screening test, not a diagnostic test. If TSH is elevated, the next step — which an endocrinologist will do automatically but a GP may not order — is a panel of tests that actually determines the underlying cause and appropriate treatment.
Tests to request if your TSH is elevated
- Free T4 (FT4) — Measures the active thyroid hormone circulating in your blood. If FT4 is also low, that's overt hypothyroidism. If FT4 is normal but TSH is elevated, that confirms subclinical hypothyroidism and changes the treatment calculus.
- Anti-TPO antibodies (Anti-thyroid peroxidase) — Tests for Hashimoto's thyroiditis, an autoimmune condition and the most common cause of elevated TSH. If positive, your likelihood of progressing to overt hypothyroidism is significantly higher, which changes the treatment decision.
- Free T3 (FT3) — Some patients convert T4 to T3 poorly; FT3 gives a more complete picture of active thyroid hormone availability.
- Ferritin — Iron deficiency causes fatigue, hair loss, and weight changes that closely mimic hypothyroid symptoms. Critically, low ferritin also impairs thyroid hormone conversion — so even if you do have a thyroid problem, untreated iron deficiency will limit your response to thyroid medication.
- Vitamin D — Deficiency is endemic in Canada (especially in winter, especially among South Asians with darker skin tone) and produces fatigue and mood changes identical to hypothyroid symptoms. South Asian Canadians are at particularly high risk.
- B12 — Often ordered alongside thyroid panels; deficiency presents with fatigue, brain fog, and neurological symptoms that overlap significantly.
Many patients with TSH 6.8 are told they don't need medication yet — and then start Levothyroxine and still feel unwell. A common reason is undetected low ferritin. Ferritin is required for thyroid hormone production and conversion. Treating hypothyroidism without correcting iron deficiency is like filling a car with fuel when the engine has a problem. This is one of the most frequently missed steps in primary care thyroid management.
When should subclinical hypothyroidism be treated?
This is where endocrinologists and GPs diverge most. There is no universal cutoff, but most endocrinologists today consider treatment for subclinical hypothyroidism when any of the following apply:
- TSH is above 5.5–6.0 mIU/L with symptoms consistent with hypothyroidism
- Anti-TPO antibodies are positive (Hashimoto's) — indicating autoimmune thyroid disease that will likely progress
- The patient is pregnant or planning pregnancy (TSH should be kept below 2.5 in pregnancy)
- There is cardiovascular risk, elevated cholesterol, or pre-existing cardiac conditions — hypothyroidism worsens cardiovascular risk profile
- TSH has been persistently elevated across two measurements three months apart
At TSH 6.8 with symptoms, most endocrinologists would not simply "monitor." They would order the full panel described above, and based on those results, would have a structured conversation about whether Levothyroxine (the standard thyroid medication) is appropriate, at what starting dose, and what the TSH target on medication should be.
The TSH target on medication matters too
One important detail that affects many Canadians on thyroid medication: the target TSH on Levothyroxine is not simply "within normal range." Many GPs dose to get TSH anywhere in the 0.4–4.0 range and consider the job done. Most endocrinologists target a tighter range — typically 0.5 to 2.5 mIU/L — for symptomatic patients. A patient whose TSH is brought from 6.8 down to 3.8 on medication may still feel unwell, and may be told their results are "normal" when in fact they are under-dosed relative to optimal function.
If you are already on Levothyroxine and still symptomatic, ask your doctor specifically what TSH target they are aiming for — and whether it's time to reassess the dose.
What to say to your doctor
"My TSH is 6.8 and I have ongoing symptoms — fatigue, [cold intolerance / weight gain / hair changes — add yours]. I'd like to request Free T4, Anti-TPO antibodies, Ferritin, Vitamin D, and B12 today. I want to understand whether this is Hashimoto's and whether treatment is appropriate at this TSH level, not just monitoring."
This framing is reasonable, evidence-based, and your GP cannot dismiss it. If you are refused these tests without explanation, that is information about the quality of your care — and a second opinion from an endocrinologist, whether through the Canadian system (where the wait may be 4–6 months) or through a specialist consultation service, is entirely appropriate.
A note on the endocrinologist wait time in Canada
In BC, the wait to see an endocrinologist through the public system can be 4 to 6 months or longer for non-urgent referrals. If your TSH is 6.8 with significant symptoms and your GP has not ordered the additional tests described above, you may be waiting months for a first specialist appointment while your thyroid condition either progresses or could have been addressed with a medication trial.
In this window, getting a written clinical opinion from an endocrinologist who has reviewed your full picture — TSH, symptoms, other bloodwork, medical history — can meaningfully change what happens at your GP visits in the interim. You will know what to ask for, what results to push for, and whether your current management approach is appropriate.