Are home thyroid tests reliable?

You can test your thyroid function at home by looking for hypothyroid symptoms and measuring your body temperature and pulse rate.

According to Dr. Ray Peat, this gives you a reliable indication of your actual thyroid function on the cellular level.

Below you find a list of some common symptoms of hypothyroidism. Instructions and are also given for how to measure your pulse and temperature.

Stress hormones can keep your pulse and temperature artificially high, therefore you need to take the measurement in a specific way, in order to estimate the thyroid function and not the effect of the stress hormones. See our instructions below. 

If you have several of the symptoms listed and your oral temperature and pulse rate are consistently significantly below 98.6°F (37 °C) and 85 beats per minute, you might have a problem with your thyroid function. 

Low thyroid function

Best way to mesure thyroid function?

When doctors measure your thyroid function they take a blood test for TSH and the thyroid hormones T4, and T4.

Blood test provides important information, however, they don’t give you the actual thyroid function on the cellular level.

Many things affect the cellular response to the circulating thyroid hormones, thus you might have a normal level of these hormones in your blood, but your actual thyroid function on the cellular level might be low. 

By measuring your body temperature and pulse rate as well as looking for symptoms of hypothyroidism you can more correctly estimate your actual thyroid function on the cellular level. 

Symptoms of Hypothyroidism

Symptoms of Hypothyroidism

The low cellular energy production of hypothyroidism leads to many different symptoms. Some common symptoms are listed below.

thyroid function and body temperature?

The oral temperature that corresponds to good thyroid functions for adults is 98.6° F (37° C). An oral temperature consistently significantly below 98.6° F (37° C) is an indication of hypothyroidism (low thyroid function).

When you measure your temperature to evaluate your thyroid function, you can use a digital thermometer under the tongue or an eardrum thermometer.

Importantly the eardrum temperature reading will be a little higher than the oral reading:

  • An eardrum temperature is 0.5°F (0.3°C) to 1°F (0.6°C) higher than an oral temperature.

Often the eardrum temperature is easier to use, as the oral temperature will be affected by any warm or cold drink you might have been consuming before measuring.

The temperature of  good thyroid function  

Mouth37.0°C  (98.6°F )
Ear37.3°C – 37.6°C (99.1°F – 99.6°F)

Mouth measurement

  • Carefully place the tip of the thermometer under the tongue.
  • With your mouth closed, leave the thermometer in place for about 1 minute until you hear the “beep”.

Ear Measurement

  • Gently tug on the ear, pulling it back. This will help straighten the ear canal and make a clear path to the eardrum.
  • Gently insert the thermometer until the ear canal is fully sealed off. Take your measurement. 

Can The temperature be invalid?

Hot weather or sleeping under an electric blanket increases the body temperature towards normal in a hypothyroid person, thus in these situations, the temperature is not valid and the pulse rate is the important factor in determining the thyroid function.

Ray Peat pulse rate

Thyroid function and pulse rate?

Pulse rate of good thyroid function?

According to Dr. Ray Peat,  a person with good thyroid function will have a resting pulse rate of about 80-85 beats per minute, with up to 90 beats per minute being healthy. 

You can use your fingers on the wrist to measure your pulse, you can also use a  pulse monitor or blood pressure monitor, which usually also gives you the pulse rate. 

Doctors say a low pulse rate is healthy?

Often doctors talk about a low pulse rate as healthy. An athlete’s resting heart rate is lower because exercise strengthens the heart muscle, which allows the heart to pump a greater amount of blood with each heartbeat. More oxygen is thereby delivered to the muscles with each beat allowing for a slower pulse rate. 

However, if you are not an athlete a low pulse rate can be an indication of hypothyroidism. A low pulse rate will result in your cells receiving less blood and thus oxygen resulting in many of the symptoms of low thyroid function.  

Thyroid function or Stress hormones?

Hypothyroid people often compensate for the low cellular energy by increasing the stress hormones, cortisol, and adrenalin.

The stress hormones are there to compensate for the low thyroid function and they keep the body temperature and pulse rate up. The stress hormones are highest in the morning before eating breakfast.

What are the signs of High cortisol?

High cortisol in the morning is common in hypothyroid people. Cortisol keeps your body temperature up into a normal range, even though you have a low thyroid function.

If your cortisol is high, there will be a drop in temperature after breakfast, as the cortisol is allowed to normalize, with increased blood sugar. 

What are the signs of High Adrenalin?

Sometimes the adrenaline is up to 40 times higher in a hypothyroid person compared to a person with good thyroid function, this leads to a very high pulse rate, which can create problems with falling asleep and waking up during the night. The high adrenaline also tends to cause cold hands, feet, and nose.

If your adrenalin is high, there will be a drop in pulse rate after breakfast, as the adrenalin is allowed to normalize, with increased blood sugar. 

stress of darkness
Ray-Peat-online-products

Test your thyroid function using temperature, pulse and symptoms?

You can separate the effect of your stress hormones from your thyroid function by measuring the temperature and pulse rate before and after breakfast. 

We recommend taking your pulse and temperature measurement upon waking and about 30 minutes after breakfast. 

It is important that the breakfast contains protein, salt, and good carbohydrates in order for the stress hormones to come down; it could be eggs with salt and orange juice or cheese with fruits. 

If your pulse and temperature fall significantly after breakfast you are running on stress hormones and not good thyroid function.

If you have good thyroid function you often wake up with a bit low temperature and pulse rate, which then after breakfast increases to an oral temperature, and pulse rate of 98.6°F (37 °C) and 80-85 beats per minute respectively. These values indicate good thyroid function and should stay stable during the day. Thus you can verify the after breakfast measurements by taking afternoon measurements too.

Thyroid Test Schema

You can use our temperature, pulse, and symptoms schema to keep track of your measurements. It is good to take the mesurements for two weeks.

Open Schema

Is My Thyroid Medication Working?

If some form of thyroid medication or thyroid supplement is used, it is essential to keep track of the pulse rate and body temperature for instance by using a chart like the one shown.

You should plot the temperature and pulse rate taken after breakfast or the measurements taken in the afternoon. 

When starting thyroid replacement therapy, T4 (storage thyroid hormone)  accumulates in the tissues, and its action will increase until equilibrium is reached, which usually takes about two weeks.

If the lines are rising so fast that they will reach the goal temperature and pulse rate in just a few days, the dose is too high (at least for the present) and should be reduced.

When the body has accumulated a steady level of thyroid hormones (which takes about two weeks) and begin to function at a higher metabolic rate, the stress hormones often begin to come down, which can lead to a pulse and temperature drop. 

The daily dose of thyroid then needs to be increased at this point. This may happen several times as the thyroid function starts to take over and the stress hormones decrease.

Dr. Ray Peat thyroid counseling

Dr. Ray Peat Based Diet Program

In our Hypothyroid Treatment Program, you can learn much more about your thyroid function, how hypothyroidism affects your whole body, and how to support your metabolism with diet, supplements, and lifestyle. 

Nutritional & metabolic counseling

Our thyroid specialist Benedicte Mai Lerche  MsC Ph.D. does online consultations with people from all over the world.

In these online sessions, we discuss your health issues, and your pulse and temperature measurements are used to evaluate your thyroid function.

Our diet advice is fine-tuned to your needs. Nutritional supplements, hormonal support compounds, and thyroid replacement therapy are recommended according to your needs. We offer both a single session and a consultation package with three sessions.