Introduction

I have been treating patients with thyroid disorders for over 15 years and the idea of sitting down and writing about thyroid is very daunting. The vast amount of information about proper thyroid assessment and treatment has filled many books. I know, I have read a number of them. Therefore, I have decided to keep this article very basic. I apologize to those that were hoping for more, but I hope that this article can at least point some in the right direction on their thyroid journey. Due to the fact that is is basic information, I would like to refer you to a website that many thyroid patients already know, ‘Stop the Thyroid Madness’. This website has been around at least as long as I have been treating thyroid (I’m pretty sure it has been around longer). It is a treasure trove of information about thyroid diagnosis and treatment.

I believe the most important information for those just looking for direction is information of symptoms, signs (clinical testing), and lab testing. So, these are the topics I will cover but, with just the basics.

Symptoms

Remember that none of these symptoms alone are exclusive of thyroid disorders. When we start to see more than one of these symptoms and have been able to rule out other disorders then we can be more confident in a thyroid diagnosis.

Hyperthyroid (too much thyroid hormone or thyroid activity)

  • Overheating – hotter than you should be for the situation
  • Low energy – not as common as in hypothyroid and is more of a burned out energy
  • Heart palpitations – strong heartbeat that can be felt in chest wall without strenuous activity
  • Rapid heart rate – heart rate approaching or above 100 bpm at rest
  • Trouble sleeping
  • Loosing weigh or underweight
  • Bulging eyes – this symptom usually occurs after a longer period of hyperthyroid

Hypothyroid

  • Cold – feeling of being cold in general and feeling of cold hands and feet. The feeling of cold feet may be seen on its own and is more diagnostic for hypothyroid
  • Low energy – especially first thing in the morning ‘hard to get going’
  • Gaining weight or overweight and can’t loose weight
  • Foggy headed and memory issues
  • Dry skin

Signs

These are tests that can be done in clinic and some can be done at home as well. Remember that most of these signs, if positive, could be due to other things as well

Hyperthyroid

  • Elevated temperature – since temperatures vary due to other issues as well it may be more diagnostic to go with the feeling of being too hot than the actual temperature. Normal temperature is considered 37.1 C so anything above this could technically suggest hyperthyroid
  • Rapid achilles reflex – you need to be familiar with a normal reflex to use this sign in your diagnosis
  • High pulse pressure – this is a higher than normal difference between systolic and diastolic blood pressure. A normal difference is 1/3 of the systolic pressure

Hypothyroid

  • Lower than normal temperature – there are less variables that would decrease temperatures so this is a better diagnostic tool for hypothyroid. Many believe that temperatures consistently below 36.4 C are diagnostic for hypothyroid
  • Slow or absent achilles reflex – the slow part is generally seen in the return phase of the reflex
  • Low pulse pressure – this is the opposite of hyperthyroid. The gap will be less than 1/3 of the systolic pressure

Lab testing

Thyroid stimulating hormone (TSH) – this hormone is released from the pituitary gland (just under the main part of the brain) and it stimulates the thyroid gland to produce thyroid hormones. Some thyroid experts suggest that TSH gives an accurate reflexion of thyroid hormone activity in 95% of people tested (ie. will miss 5% of thyroid cases). This is when the proper ranges are used. The bigger issue is that most labs post reference ranges with a maximum of up to 6 mIU/ml even though most thyroid experts will say the the maximum should be 2.5 and some saying 2.0 as the maximum. Most doctors will use the lab range as their guide, so will diagnose, based on this one lab, that their patient does not have a thyroid issue and all their symptoms must be something else. Even if a patient has a TSH under 2.5, if they have symptoms and signs that suggest hypothyroid it needs to be investigated further. Once you start treating someone with thyroid hormones the value of the TSH test changes. One thyroid expert suggests (this comes from about 15 years ago) that TSH is only a reliable test in 70% of patients taking thyroid hormone. In my experience I would put this number down to more like 50%. This means that when you get patients on enough thyroid hormone to eliminate their symptoms, 50% of these patients will have optimal levels of TSH when tested and 50% will have lower than optimal levels (mostly very close to zero).

Thyroxine (T4) and thyronine (T3) (T1 and T2 will not be discussed here)- you may see these hormones under slightly different names but most just use the nomenclature T4 and T3. T4 is generally considered to be inactive and T3 is the active hormone. T4 has to be converted to T3 in the liver or the target cells to be activated. Labs usually offer total T4 and total T3 as well as freeT4 and freeT3. Most thyroid experts prefer freeT4 and freeT3 for reasons I will not go in to here. Testing for these hormones is variable and reference ranges are variable. There is also variation due to influence of other hormones, something referred to as pooling, and excretion. There is even another thyroid hormone, called reverseT3, that effects the T4 and T3 balance and activity. All this said there is no consistently optimal range for freeT4 and freeT3. Generally, with the labs done in the province of Alberta, I am looking for a freeT4 around 19 pmol/L and a T3 of around 5.5 pmol/L. In BC I was looking for a freeT4 of around 13.5 pmol/L and a freeT3 about the same as Alberta, 5.5 pmol/L. Remember, there are other variables to consider, so the optimal for the individual patients are somewhat variable as well.

Thyroid antibodies (aTPO, aTG, aTSH) – remember we are sticking to the basics so I will not go in to the antibodies this time.

I hope this was helpful. Remember the ‘Stop the Thyroid Madness’ group. I have no connection to them other than I have had a lot of patients over the years that have received a lot of helpful information from them.

All the best in your Journey