Test your thyroid 

The thyroid gland controls the body’s metabolic rate and hypothyroidism (low thyroid function) leads to low cellular energy production. Because thyroid function is so central to the body’s energy production, hypothyroidism can lead to many different symptoms, as the tissues do not function optimally!

According to Dr. Ray Peat looking at symptoms as well as measuring body temperature and pulse rate is a good way to get an indication of your metabolic rate/thyroid function.

Below you find a list of the symptoms, which are connected to low thyroid function. Instructions are also given for measuring pulse and temperature.

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

Symptoms of low thyroid function 

  • Acne
  • Allergies
  • Anemia
  • Arteritis
  • Candida
  • Blood sugar issues
  • Cold hands and feet
  • Digestive problems
  • Depresion
  • Fatique
  • Hair and skin problems
  • Headaches
  • High cholesterol
  • Infertility
  • Menstrual problems (PMS, endometriosis)
  • Muscle and joint pain
  • Premature aging
  • Infection and inflammation
  • Water retension
  • Weight problems (gain or loss)
Ray Peat pulse rate

Pulse & temperature

Hypothyroid people can compensate for the low cellular energy by increasing the stress hormones (cortisol and adrenaline). The stress hormones keep the body temperature and/or the pulse rate up. Often the stress hormones are high upon waking, which can create high temperature and pulse values in the morning. 

If the stress hormones are high, there will be a drop in temperature and/or pulse rate to the hypothyroid level after breakfast, as the stress hormones are allowed to normalize, with the increasing blood sugar. Thus, by measuring the temperature and pulse rate before and after breakfast, it is possibly to separate the effect of the stress hormones from the actual thyroid function.

If some form of thyroid medication is used, this temperature and pulse method is a good way to measure if the right kind and amount of medication is given. You can read more about thyroid replacement therapy in Module 16.

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.

Charts & tabels

It is important that the breakfast contains protein, salt and good carbohydrates in order for the stress hormones to come down; it could for instance be eggs with salt and orange juice or cheese with fruits. 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.Keeping a chart for 14 days of both temperature (taken orally, under the tongue) and pulse rate measured before and after breakfast will give a good impression of the metabolic rate, as well as the stress hormones. You can find tabels to note down your measurements below.

It is good to wait about 20 minutes after eating to take the after breakfast measurements. Normally, the temperature and pulse rate will increase when eating breakfast to values of about 98.6°F (37 °C) and 85 beats per minute respectively. These values indicate good thyroid function and should stay stable during the day. 

Ray Peat temperature