Knowing the root cause of one's hypothyroidism? How to know if it's Hashimotos Disease?

Question

Ever since I was a teenager, I've been treated for hypothyrodism (underactive thyrodid). However, I don't recall the official diagnosis process and am not sure if it was ever conducted. My grandmother, mother, older sister, who all lived with me at the time and saw the same doctor, had hypothyrodism and were treated for such.

Needless to say, I'm not sure if my general-practitioner 15 years ago, just skipped the cause/root of my hypothyrodism and just went straight to the treatment (which at the time was Armour Thyroid Medication wherein dosages were determined by compairson to my TSH levels indicated on my blood-tests) or not. However, I've seen endocrinologists since then and know for sure that I have hypothryoidism (I'm now on Synthroid), but no one ever told me the reason.

I was reading online that:

Hashimoto's disease is the most common cause of hypothyroidism in the United States. http://www.mayoclinic.org/diseases-conditions/hashimotos-disease/basics/definition/con-20030293

I was wondering if I can ask a doctor now, years later, if they can tell me why I have hypothyroidsm, and if it at all relates to Hashimoto's Disease? I have also been diagnosed with borderline Lupus and Fibromyalgia (other autoimmune diseases), and was wondering if these all interrelate in any way?

Would knowing the reason for my hypothyroidism make any difference?

Answer 1

I am answering this almost two years after it was asked, but I hope an answer can still be useful!

Hashimoto’s Disease

You are correct that Hashimoto’s disease (also known as Hashimoto’s thyroiditis) is the most common cause of hypothyroidism in those aged over six. In younger children hypothyroidism is most often congenital. So yes, you almost certainly have hypothyroidism due to Hashimoto’s disease.

Hashimoto’s thyroiditis is an autoimmune disease. This means that something triggers the immune system to produce antibodies that cross-react with normal parts of the body. People with Hashimoto’s disease can have antibodies in the blood to various components of the thyroid gland. The most common are anti-thyroid peroxidase (anti-TPO) antibodies. You may have had a blood test for this and you could certainly ask your family doctor or endocrinologist. Either way, the treatment is similar to other causes; namely replacement of thyroid hormones with levothyroxine.

Autoimmune disease in general

The origins of autoimmune disease seem to be a complex mix of genetic and environmental factors and possibly pathogens. Much autoimmune disease is due to various forms of immune hypersensitivity. Specifically, Hashimoto’s thyroiditis is an example of type 4 hypersensitivity (along with coeliac disease and multiple sclerosis), while type 1 causes most allergies and anaphylaxis.

A good example is autoimmune disease after infection by Group A streptococcus bacteria (a common cause of throat infections, skin infections, scarlet fever etc). In some people, the antibodies that the body makes against streptococcus will cross-react with other body tissues and damage them, causing a number of conditions:

• Rheumatic fever and rheumatic heart disease (type 2 hypersensitivity)
• Glomerulonephritis (type 3 hypersensitivity)
• Guttate psoriasis
• Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS)

See this paper for more information about autoimmunity after streptococcal infection. This is an example of type 3 hypersensitivity.

Other Points

Various autoimmune diseases are associated with one another. Having one can make another more likely. For example, there is a link between type 1 diabetes and autoimmune hypothyroidism. You mention that you may have lupus, which is also autoimmune.

You also mention fibromyalgia. Currently, fibromyalgia is not thought to be an autoimmune condition. Proposals of an autoimmune cause have not yielded evidence of this in research. It is likely to result from a complex interplay of internal and external factors with neurochemisty and neurophysiological processes. There is some overlap in symptoms, but this is not surprising as pain, stiffness, fatigue and low energy are some of the most common symptoms there are and can have many causes.

I see from another question of yours that you had a bad experience with a general practitioner taking the very outdated view that fibromyalgia is not a real condition! It most certainly is real, even if not well understood yet, and can cause a lot of suffering. Whatever the underlying cause turns out to be (there may be several), it does not have to have an autoimmune origin to be real! :)