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Can Lyme Disease Affect The Thyroid?

Lyme disease is a parasitic infection caused by the spirochete bacteria Borrelia burgdorferi. The bacteria are found in ticks throughout the world, although the tick that most commonly carries this bacteria in the UK is known as the Sheep tick or Castor Bean tick. When ticks attach on to their host by way of ‘questing’ – reaching out from the tip of a blade of grass and grabbing hold – they bury their head into the skin and begin to feed on the host’s blood. A tick can remain on one given host for up to several days before dropping off and moulting into the next stage of their life cycle.

The bacteria introduced to the body via the tick bite travels through the bloodstream, affecting many different systems within the body. The American Lyme Disease Foundation (ALDF) describes Lyme disease as a ‘multisystem inflammatory disease that affects the skin in its early, localized stage, and spreads to the joints, nervous system and, to a lesser extent, other organ systems in its later, disseminated stages.’ This disease can be incredibly damaging to many parts of the body if not caught in time.

What are the symptoms of Lyme disease?

When first bitten by a tick and infected with the bacteria, patients may notice symptoms similar to that of the common flu, making a diagnosis of Lyme disease rather difficult to obtain. The symptoms can include fever, dizziness, fatigue, headache, joint and muscle pain, loss of appetite, and general feelings of malaise. A red bull’s eye rash known as erythema migrans is also known to show up on an infected person, although it doesn’t always do so. The difficulty with diagnosing Lyme disease right at the start is also due to the fact that the symptoms don’t often present themselves until 7-10 days after a tick bite, making the connection hard to recognize. However, if caught early enough, a regime of antibiotics is often enough to cure the disease.

Sometimes, however, the disease unfortunately progresses to the chronic stage, leaving permanent symptoms that the patient will likely struggle with the rest of their lives. Such chronic symptoms can include progressive arthritis, mood swings, difficulty in cognitive functioning, facial palsy and other neurological difficulties that can affect mood, temperament, concentration and memory.


Fatigue and other flu-like symptoms are common indicators of Lyme disease.


How does Lyme disease affect the thyroid?

This condition can affect many parts of the body, but if you’re wondering ‘can Lyme disease affect the thyroid?’, the answer is yes. Another symptom of Lyme disease is that it can cause hypothyroidism in some people. Hypothyroidism is when the thyroid (the butterfly-shaped gland at the front of the neck) does not produce sufficient amounts of the thyroid hormone. The thyroid gland plays a significant role in many operations within the body, including metabolism, weight management, body temperature, heart rate, fertility and cholesterol levels. When the thyroid isn’t operating properly, this can cause a whole range of problems in the body. Some of the symptoms of hypothyroidism mirror the symptoms of Lyme disease, making it somewhat difficult to recognise in a patient who already has Lyme disease. The symptoms can include fatigue, feeling weak, cold extremities, difficulty concentrating, depression and difficulty recovering after activity.

What is Hashimoto’s thyroiditis?

Some research has also shown that the same bacteria that causes Lyme disease can also trigger Hashimoto’s thyroiditis, which is a common cause of hypothyroidism. Hashimoto’s thyroiditis is an autoimmune disease where the body’s immune system attacks the thyroid, gradually killing thyroid cells. This in turn causes the thyroid to not operate properly, eventually causing symptoms of hypothyroidism. When the thyroid cells are first being attacked by the immune system, it causes brief periods of hyperthyroidism, where the thyroid is almost over-active in order to compensate. During this period of hyperthyroidism, the patient might experience such symptoms as sweating hands, anxiety, fast heartbeat, diarrhoea, and quick weight loss.

As more thyroid cells are killed, the thyroid is unable to operate properly and the patient will then experience symptoms of hypothyroidism, which mimics the symptoms associated with Lyme disease. Because Hashimoto’s thyroiditis presents in such vague symptoms, it is often misdiagnosed as being anxiety, depression, bipolar disorder, fibromyalgia, chronic fatigue syndrome or PMS. It is very important to get the proper tests done in order to determine whether or not a patient has this disease.


Sweating hands are a symptom of hyperthyroidism.


How do you test for Hashimoto’s thyroiditis?

In order to determine whether a patient’s symptoms are due to Lyme disease, a related co-infection, or hypothyroidism, doctors will likely order a blood test to check for thyroid antibodies, although this type of testing isn’t always completely accurate. Another test doctors will request is the TSH (Thyroid Stimulating Hormone) to screen for thyroid disorders. For Hashimoto’s patients, however, this test is not always conclusive either. Because Hashimoto’s is an autoimmune disease, doctors need to also check thyroid peroxidase (TPO) antibody and antithyroglobulin antibody. If these antibodies are elevated, then a diagnosis is made.

While the exact cause of Hashimoto’s disease is not certain, there are several chronic infections that are known to trigger the disease, including Lyme disease, HHV6 and the Epstein Barr virus. Any illnesses that cause an imbalance to the immune system can trigger the disease. Patients who are already diagnosed as having one of these chronic infections and are noticing new symptoms similar to that of Hashimoto’s thyroiditis should see their doctor immediately and begin testing for the disease. Once a diagnosis is confirmed, there are treatments available to help, such as hormone replacement therapy, medical and nutritional approaches.