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More than 20 million people nationwide suffer from a condition called neuropathy. Neuropathy is a condition when the nerves located outside of the brain and spinal cord are damaged, resulting in weakness, numbness and pain usually felt in the hands and feet. More severe cases can also cause disturbances in digestion, urination, and circulation throughout the body. This article explores whether there is a connection between hypothyroidism and neuropathy. Does one cause the other, or is one a result of the other? Let’s dive in.
Neuropathy or peripheral neuropathy (used interchangeably), stems from the peripheral nervous system. This system sends information from our brains and spinal cord to the rest of the body. Cases of peripheral neuropathy can be caused by traumatic injuries, infections, nutrient deficiencies, metabolic problems, diabetes, and exposure to toxins. Those with neuropathy experience sensory symptoms such as pain that is described as stabbing, burning, or tingling. Some experience motor symptoms such as muscle weakness and paralysis, muscle atrophy, and uncontrolled muscle movements. Others have autonomic symptoms such as blood pressure changes, trouble with sweating, gastrointestinal issues, sexual dysfunction, and changes to the eyes and sight.
Some common signs of hypothyroidism include muscle weakness, mental sluggishness, and an intolerance to the cold. Patients tend to also develop numbness, decreased sensation, slowed muscle contractions, and a loss of reflexes.
Are neuropathy and Hypothyroidism connected? Various studies have shown that there can often be a connection between neuropathy and hypothyroidism. A clinical study of a 58 year old woman who was admitted to the hospital with a history of progressive weakness in both lower extremities, had a 20-year history of hypothyroidism, and was being medicated with levothyroxine and metformin for type II diabetes. After careful examination of her symptoms and various tests, it was concluded that her peripheral neuropathy was caused by hypothyroidism.
Another study of a 60 year old woman, resulted in the improvement of both thyroid function and neuropathic pain intensity. This patient initially complained of sensations of severe burning feet. After neurological examination, results demonstrated mild sensory neuropathy. Other exams showed subclinical hypothyroidism and over the course of 6 and 12 months, this patient began various therapy experiencing an improvement in both conditions concluding that even subclinical hypothyroidism is a possible cause of sensory neuropathy.
So the question now bears - can hypothyroidism can and/or exacerbate symptoms of neuropathy? The short answer is yes. In most cases of untreated hypothyroidism, neuropathic pain can increase and become more severe. One of the reasons for this is because hypothyroidism can cause fluid retention, resulting in swollen tissues that can put pressure on the peripheral nerves. It is recommended that maintaining a healthy weight can help to strengthen affected limbs.
A study out of Kosar Hospital in Semnar, Iran evaluated the case of 154 patients - some with subclinical hypothyroidism and others with eurthyroid, or normal thyroid function. This study concluded that the severity of neuropathy was higher in those patients with subclinical hypothyroidism.
Nutritional deficiencies can cause neuropathy or even exasperate already present symptoms due to damage of the peripheral nervous system. Vitamins such as B12, B6 and E as well as toxicity levels in mercury and arsenic should be evaluated.
Patients with a Vitamin B12 deficiency can experience damage to the myelin sheath that surrounds and protects the nerves. Without this protection, the nerves cannot function properly, causing symptoms of neuropathy to occur.
Nutritionally, vitamin B12 can be ingested through adequate sources of grass-fed red meat, poultry, eggs, and wild-caught fatty fish. Whereas toxicity of arsenic exposure can cause idle sensory dominant peripheral neuropathy.
Treating either hypothyroidism or neuropathy begins first with preventative care. Early stages of either condition help to get a timelier start on both detection and treatment. Some of these symptoms and conditions can go undiagnosed, especially if the symptoms start mild.
If you suspect that you might be experiencing one or the other, talk to your healthcare provider as soon as possible before symptoms worsen. It is also advised to consider nerve conduction studies in both motor and sensory nerves of the upper and lower extremities to rule out a neuropathy diagnosis.