Testing your thyroid levels: what you need to know

The thyroid is one tiny gland with a huge amount of power. Thyroid function can impact everything from sleep to stress to even fertility. Here’s how you can check in with your thyroid and what you can expect to learn from your results.

Table of Contents

Is there a thyroid test?

The best way to check in with your thyroid is with a TSH blood test. The test looks into how much thyroid-stimulating hormone (TSH) your body is producing and gives you insight into thyroid health.

Why is TSH so important? When the thyroid is overactive or underactive, the pituitary gland sends a helpful message (via TSH) to release the right amount of thyroid hormone into the bloodstream. 

Higher TSH levels indicate an underactive thyroid, and lower TSH levels indicate an overactive thyroid.

Where is your thyroid
Test your thyroid with a TSH blood test.

Which thyroid hormones should be tested?

At Modern Fertility, we always measure your TSH — and if your results show that you might have thyroid dysfunction, we’ll follow up with a free thyroxine (or fT4, another important thyroid hormone) test at no additional cost.

33% of Modern Fertility users discover a thyroid hormone result that’s worth discussing with a doctor before trying to get pregnant. (If you’re thinking about having kids one day, keep in mind that medical guidelines recommend achieving a TSH level below 2.5 uIU/mL prior to conception.)

Thyroid conditions are highly treatable, so checking in with your levels can help you stay on top of any future problems.

Third of thyroid test results require doctor
Thyroid hormone tests often measure both TSH and fT4 levels.

What is considered low thyroid (TSH) in women?

If your test comes back with a TSH level below .4 uIU/mL, that typically suggests an overactive thyroid — aka hyperthyroidism

If you have hyperthyroidism, you might experience the following symptoms:

  • Unintentional or unexpected weight loss
  • Rapid heartbeat, or tachycardia
  • Irregular heartbeat, or arrhythmia
  • Pounding of the heart, or palpitations
  • Increased appetite
  • Anxiety and irritability
  • A slight tremor in the hands or fingers
  • Sweating
  • Changes in the menstrual cycle
  • Changes in bowel movements
  • An enlarged thyroid (or goiter)
  • Skin thinning and brittle hair
Normal Thyroid (TSH) levels chart
Chart of TSH levels and the low, normal and high range.
What is considered high thyroid (TSH) in women?

If your test comes back with a TSH level above 4.0 uIU/mL, that typically suggests an underactive thyroid — aka hypothyroidism.

If you have hypothyroidism, you might experience the following symptoms:

  • Fatigue
  • Increased sensitivity to cold
  • Constipation
  • Dry skin
  • Weight gain
  • A puffy face
  • Voice hoarseness
  • Muscle weakness, aches, and stiffness
  • Elevated blood cholesterol level
  • Joints pain or swelling
  • Heavier or irregular menstrual periods
  • Coarse hair and hair loss
  • Brittle nails
  • Slowed heart rate
  • Depression
  • Impaired memory
  • Enlarged thyroid gland (goiter)
Thyroid and fertility: What’s the connection?

Studies show that when there are higher or lower levels of thyroid hormones, that can alter reproductive hormones and disrupt the menstrual cycle — which makes conception more difficult. 

But just because you have hypo- or hyperthyroidism doesn’t mean you can’t get pregnant. In one study of a group of almost 400 women suffering from infertility, 24% of participants were found to have hypothyroidism — but within a year of treatment, 76% were able to conceive.

Thyroid and uterus connection
Thyroid hormone levels can have a big impact on fertility.

What’s the easiest way to test your thyroid?

Modern Fertility measures your thyroid levels using the same test that a specialist at a fertility clinic would use — but you can do it from the comfort of your couch for a fraction of the price. 

With our test, you’ll also get access to:

  • Physician-reviewed reports based on your results, including one focused on thyroid hormone levels and any health implications
  • A free 1:1 consult with our fertility nurse
  • Online tools to track hormone changes over time and help you plan your timeline for kids
  • Access to our weekly live Q&As
  • An invite to the Modern Community to connect with others and get your questions answered
Thyroid test online reports
Testing your thyroid hormones is easy (and affordable) with Modern Fertility.

Meet Modern Fertility

We’re on a mission to revolutionize women’s health, starting with our at-home fertility hormone test. Whether you’re years away from kids or thinking of trying soon, we’ll guide you through your fertility hormones now so you have options later.


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