This post likely contains affiliate links - if it links to Amazon then it is an affiliate link! As an Amazon Associate I earn from qualifying purchases.

So far as the best estimates go, upwards of 15 percent of American women develop hypothyroidism during their adult lives.

So far as my best guess can contribute to those numbers, I think perhaps a whole hell of a lot (specific, eh?) of additional women suffer from ‘sub-clinical’ hypothyroidism. Sub-clinical means that your blood test results do not meet the official requirements for a thyroid disorder as determined by the medical community, but you still experience symptoms as a result of thyroid deficiency.

So hypothyroidism is rampant. Another statistic even more striking than those I’ve already discussed is the number of women who SHOULD suspect they’ve got a thyroid problem and/or get treatment for it but do not. The American Association of Clinical Endocrinologists say the number of women undiagnosed is equal to the number diagnosed. So if 8 million American women know they have hypothyroidism, then 8 million of us also have it, but do not know.

There are two great thyroid books that I like to recommend that can help you get a better picture of how your thyroid is working.  Those are “Stop the Thyroid Madness” and “Why do I Still Have Symptoms When my Lab Tests are Normal?”


Thyroid function is complex. Your thyroid gland works only after receiving a “green light” signal for production by the pituitary gland, which comes in the form of Thyroid Stimulating Hormone (TSH). It then makes T4 in high amounts, and then T4 is converted to T3 by the liver. T3 is the final form of thyroid hormone and is responsible for delivering energy to all of the cells in your body.


The consequences of developing a problem somewhere in this production process can be dire. They include extreme fatigue, weight gain, mental disorders, and infertility…for just a few examples.

Rectifying hypothyroidism can be genuinely lifesaving.

So it’s important to know if you’ve got it! Experiencing one of the following symptoms or engaging in one of the practices may not be enough cause for you to leap into concern, butseveral in conjunction may indicate it’s time for you to get a thyroid check-up.

Here are 19 tests for hypothyroidism:

1) You’re tired.

Unfortunately, fatigue is one of the most common complaints for just about every health condition out there. It is particularly strongly associated with thyroid disorders, however. The thyroid system’s entire job is to provide energy to your cells. If you’re extremely tired even though you are well-rested, your thyroid may be to blame.

Because fatigue is so common, it may be best to see if you meet any of the other criteria on this list before proceeding.

2) You suffer menstrual disorders or hormone imbalances such as PMS or PCOS.

The thyroid gland is a part of a delicate team of glands in your body called the HPA (and T, and O) axis. The hypothalamus, pituitary gland, thyroid gland, ovarian tissue, and adrenal glands all work in tandem to produce hormones that run your body. Reproductive hormone irregularities are a big red flag for disruption anywhere in the HPATO axis.

If your estrogen levels are high, then there’s a decent chance your thyroid levels are low. How do you know if estrogen is high? Best of all, get your blood tested. If you cannot do that, you can perhaps infer your estrogen status from your menstrual symptoms. If you suffer from cramps and PMS, there’s a decent change your estrogen levels are high. Estrogen is the primary cause of PMS, cramps, heavy bleeding, and lengthy periods.

Estrogen and thyroid hormone are antagonists to each other in the bloodstream. When one goes up, the other often goes down.

Additionally, if you have Poly Cystic Ovarian Syndrome, you may also wish to consider hypothyroidism as a cause, as low thyroid levels are one of the easiest ways to cause the reproductive system to slow down.

If you do have PCOS, you may want to read my delightfully helpful book PCOS: Unlocked.

3) You are constipated

The purpose of thyroid hormone is to deliver energy to cells. If you have insufficient thyroid function, then bodily functions slow down.

Digestion is one of them.

Combined with other symptoms, constipation is a red flag for thyroid disruption.

Another way your gut may be involved in your thyroid health is via an autoimmune disease.

90 percent of hypothyroid cases are actually caused by Hashimoto’s Thyroiditis, which is an autoimmune disease. Autoimmune disease originates in an unhealthy gut. Unhealthy guts often have perforations in their lining, which allows toxic particles to pass into the bloodstream. The immune system mounts an attack against these particples. This is generally a good thing, except that your immune system can be so panicked that it accidentally starts attacking your own human cells – like thyroid cells – too.

If your digestion is significantly impaired in any fashion, this may be directly related to your hypothyroid problems. Get tested for this by asking a doctor for a test for Hashimoto’s antibodies. These are the molecules in your blood that mount the immune attack on your thyroid gland. If you have elevated amounts of these antibodies, then your hypothyroid problems are likely from your unhealthy gut.

Your gut can be supported by taking a probiotic supplement, eating probiotic rich foods like sauerkraut, and by consuming gelatin.

4) You are cold.

Ever wonder why women are so much colder than men? Thryoid hormone is a furnace, keeping cells firing at the right energetic rate to stay warm. If you are constantly cold, especially relative to the people around you, this may indicate a thyroid issue.

It’s best to keep track of your basal body temperature.  This will help you tell if you are consistently cold.  A mercury thermometer like this one is suggested because it is much more accurate than a digital.

5) You have low blood pressure and/or poor circulation

Because having low thyroid levels slows down most body functions, it makes sense that the blood would slow down a bit, too. Slowed blood movement means low blood pressure, which itself can cause dizziness and fatigue.

Low blood pressure ad poor circulation can also cause numbness or coldness in the extremities. This happens via the simple mechanism of decreased blood flow to the extremities as well as decreased energetic rate.

This is another one of those “womanly” things – have you ever snuggled with a person who was shocked by how terribly cold your feet are? Your circulation and/or thyroid health may be to blame.

6) Your skin, hair, and nails are dry and brittle 

The thyroid gland helps skin and hair cells stay connected, lubricated, and being produced at a steady, happy pace. When thyroid levels are low, the quality of your “external” cells decreases.  (This oil can help support healthy hair, skin, and nails)

7) Your voice is hoarse

This is one of the markers of hypothyroidism I personally do my best to forget about, since I often have a hoarse voice – most particularly when I am stressed out or not sleeping well.

The reason your voice becomes hoarse on hypothyroidism is that the thyroid gland is located very close to your vocal chords. The thyroid gland swells and produces excessive “nodules” when under duress, which press on your vocal chords.

8) Your neck is swollen

The medical term for this is “goiter” and is directly related to having a hoarse voice. When unhealthy, the thyroid gland swells. This can be small and only detectable via touch (your doctor is trained to do this), or in massive proportions that can make it quite obvious.

Most cases of goiter worldwide are caused by iodine deficiency.

Most cases of goiter worldwide are caused by iodine deficiency.

9) You experience mental issues such as brain fog or poor memory retention

Here we have more “slow-down.”

If your thyroid levels are low, your brain gets sluggish. It’s hard to remember things and to focus. More thyroid hormone could make you sharper, more aware, and more appreciative of your surroundings.

10) You experience mood issues, particularly depression

Depression and hypothyroidism are linked via the neurotransmitter serotonin. Serotonin is largely responsible for feelings of peace, calm, contentedness, and being happy enough to get out of bed in the morning. Thyroid hormone regulates serotonin production. Less thyroid means less serotonin. It also means less of other good stuff, like dopamine, which is another neurotransmitter that makes you feel happy to be alive.

Depression and thyroid can also be linked via gut permeability, like we discussed earlier. How? If your underlying problem is poor gut health, then serotonin will be impacted, too — as 95 percent of the body’s serotonin is located in the gut (!).

11) You experience relentless weight gain or extreme difficulty maintaining a healthy weight

Given that lots of body processes slow down when you are hypothyroid, it should come as no surprise that fat burning is one of them.

In fact, it is one of the primary systems affected.

Most studies indicate that thyroid hormone levels go up when one becomes overweight. This is because the body is attempting to burn off that fat as quickly as possible. So you may be overweight and have “healthy” thyroid levels.

But you may also be under-, normal-, or over-weight and have hypothyroidism making your weight maintenance difficult. For anyone of any size, decreased thyroid activity directly decreases caloric expenditure.

My new book Weight Loss Unlocked can help you to healthfully lose weight while supporting your body’s hormonal balance and thyroid.

12) You have a low sex drive

Low libido is another indicator that your hormones simply are not up to snuff. Sex drive is always one of the first things to go when the reproductive system is stressed. Any dysfunction in the HPA axis likely means there’s dysfunction elsewhere, such as in the thyroid gland.

13) You are stressed

If you are psychologically under any kind of duress, your thyroid hormone levels will most likely drop. Your hypothalamus is highly attuned to stress and happiness levels.

If you are physically under any kind of duress, such as by exercising excessively or undereating, your hypothalamus will also know this, and it will detect this as a sign that it needs to shut it all down.

Both psychological and physical stress are major thyroid buzzkills.  Know this well, and do your absolute best to reduce stress as much as possible.

14) You eat a very low carbohydrate diet

Very low carbohydrate diets – such as those that only have vegetables as a source of carbohydrate without starchier varieties like potatoes or fruit or rice in the diet – can hinder the conversion from T3 to T4.

Your liver needs carbohydrates in order to produce T3 adequately. So beef up your carb intake if on a VLC diet — up to at very minimum 80 grams a day (about three servings of fruit or starch), and perhaps you may see your thyroid levels tick back up.

15) You do not eat seafood or consume iodized salt

Iodine is necessary for thyroid function.

Goiter was sweeping the nation in the early 20th century. Iodine was added to table salt in 1924, and this helped a lot of Americans. The vast majority of hypothyroid cases worldwide are in fact due to iodine deficiency. This isn’t the case in the states precisely because of the iodized salt, yet iodine deficiency remains a potential threat. Without iodized salt iodine is quite rare in the diet, except for in fish or seaweed.

If you suffer hypothyroid symptoms and also do not consume iodized salt, consider adding some back in to your diet, as this could be hindering your thyroid hormone production. Consuming fish can help, and especially seaweed, if you choose not to go with the iodized salt.

Note: While a diet low in iodine can cause hypothyroidism, supplementing with iodine in the case of a thyroid problem is not always the best idea. Iodine supplementation can aggravate autoimmune disorders associated with the thyroid gland. So nourish your thyroid gland as best you can, and be sure you do not have an autoimmune condition before considering significant iodine consumption. Iodine in natural foods and some salt should be fine for most.

16) You eat a lot of greens

Leafy green vegetables such as kale, spinach, Brussels sprouts, and broccoli all contain high levels of a group of molecules called “goitrogens.” Goitrogens are known to cause goiter, largely because they interfere with iodine uptake by the thyroid gland. This makes it impossible for your body to synthesize sufficient levels of thyroid hormone.

In reasonable doses for a healthy human being, goitrogens are not a problem. Yet for someone predisposed to thyroid issues or who eats a high quantity of greens (think: in excess of a few servings every day), these can actually be a problem. This is especially true if you eat them raw. Cooking greens neutralizes the goitrogens, to an extent. But consuming them raw, or fermented (think: kimchi or sauerkraut), then you are in for a hefty dose of goitrogens.

17) You take a lithium-based mood stabilizer

Lithium directly inhibits thyroid hormone production.

Lithium can be salvific for people who suffer from bi-polar and other mood disorders. In this case, it may be worth the trade-off.

The trade-off is not all that clear-cut anyway. The thyroid gland can be supported by iodine supplementation or thyroid hormone dosing if you are also taking lithium. So there’s no saying you must come off of lithium in order to eliminate thyroid symptoms. This is just one known, very real cause of hypothyroidism.

18) The outer third of your eyebrows is unusually thin

This one symptom may seem a bit off the wall. Really? Thin eyebrows?


In fact, I have had vanishingly thin outer eyebrows my entire life. In the last year or so they have grown thicker… and I am not alone in this.


Me in 2011. Please ignore my hand gesture – this is the best photo I could find of my eyebrows. Even here, my brows are penciled in. I’ve been penciling in outer eyebrows since junior high school.


This study found that 24% of hypothyroid patients have thin eyebrows. Hypothyroid patients tend to lose hair generally, as the body just becomes less good at producing it. Eyebrow hair is particularly at risk, so skinny eyebrows are a good if harmless red flag for investigating your thyroid health.

19) You do not have these blood test results

A blood test is one of the best ways to know if you have a thyroid issue. Of course, blood tests aren’t bulletproof, but then again, nothing is.

Here is a list of blood test results where one of my favorite experts Dr Amy Myers and I both believe the healthy ranges are. Ideally, you want:

  • TSH 1-2 UIU/ML or lower (If TSH is too high this means the body is trying to get the thyroid gland to make T4 and T3 but it isn’t happening)
  • T4  >1.1 NG/DL (High T4 can also signal hypothyroidism if T3 is low)
  • T3 > 3.2 PG/ML
  • Reverse T3 (something you produce under stress) less than a 10:1 ratio Reverse T3:Free T3
  • TPO (these are antibodies) – <9 IU/ML or negative
  • TgAb (also antibodies) – < 4 IU/ML or negative


… Which concludes our list! To read more about thyroid disease, stay tuned for more in this series, and be sure to check out Chris Kresser’s articles, which are comprehensive and very, very smart.

Note - some links above may contain affiliate links. You don't pay more, but we get a small cut to help keep this organization running. It's tough to balance ethics with the need to stay alive. Thank you for your patience and understanding!