Migraines are co-morbid with several other conditions, including hypothyroidism. But can migraines actually cause the disease? While rare, it seems that they may.

Migraines can both be caused by stress and cause stress; and stress affects the entire body, especially endocrine function. Therefore, a connection between migraines and hypothyroidism is not out of the realm of possibility.

Hypothyroidism Defined

The thyroid is a bow tie or butterfly-shaped gland in the neck just beneath the vocal cords. It secretes two essential hormones related to healthy bodily functions: thyroxine and triiodothyronine. These are two of the hormones that control core body temperature, protein production, and metabolism.

Thyroid disorders include conditions in which the thyroid is overactive, secreting too much of one or more hormones, as well as conditions in which it is underactive, secreting too little hormone. The latter is called hypothyroidism.

People with hypothyroidism have slower than normal metabolisms and often feel cold and sluggish. Low thyroid can exacerbate the incidence of migraines, but the link between the two conditions is more complicated than it seems.

Symptoms of hypothyroidism also include hair loss, weight gain, constipation, and irregular menstrual cycles. It is a rare disorder, and in instances of subclinical hypothyroidism, no symptoms may be apparent. It may be discovered only through blood tests showing slightly elevated TSH (thyroid stimulating hormone) and T4.

The Statistics of Migraines and Hypothyroidism

About 12% of Americans experience migraines either chronically or episodically. Only around 2% of Americans suffer from hypothyroidism. However, about one-third of that 2% with underactive thyroid have a history of headaches. 

• Half of the patients diagnosed with hypothyroidism have a history of migraines before the diagnosis.
• Women are three times more likely to experience migraines than men. According to Johns Hopkins University, the ratio is 18% to 6%
• Women are 18 times more likely to suffer hypothyroidism than men, according to the Society for Endocrinology.
• In women, just over half of migraines are related to the menstrual period. However, the average age of a woman diagnosed with hypothyroidism is 51, when they are undergoing or have completed menopause, which typically causes alleviation of migraine symptoms.
• Since migraines can persist after menopause, hypothyroidism may be related to migraines; however, there is also a strong argument that migraines may predispose a patient to hypothyroidism in return.

The Cincinnati College of Medicine found that individuals with a history of migraines showed a 41% increased risk of developing hypothyroidism in comparison to the general population.

Another study at the University of Cincinnati by researcher Susan Pinny, Ph.D., found hypothyroidism shows not only a higher association in women, but the risk of developing it increases with age, obesity, and certain medications.

Neither condition is life-threatening, but both decrease the quality of life without appropriate treatment.

Hypothyroidism and Migraine Research

A study from the journal Headache entitled Headache Disorders May Be a Risk Factor for the Development of New Onset Hypothyroidism is the most extensive study to date suggesting links between headaches, migraines, and thyroid disorders.

The lead author is Andrew Martin, at the time a fourth-year medical student at the University of Cincinnati College of Medicine. The study also included a researcher named Vincent Martin, MD.

The research involved 8,412 people monitored over 20 years and found patients with pre-existing headache disorder, not just those with migraines, had a 21% increased risk of developing hypothyroidism. Thyroid function was measured every three years over two decades. Anyone with a prior history of thyroid disease or abnormal thyroid test results at the beginning of the study was excluded.

The study not only found a link between the risk of developing thyroid disorders after suffering migraines, but it also found the severity of the migraine symptoms trended with the severity of thyroid disease.

As it happens, a connection between subclinical hypothyroidism had already been found in the pediatric population. When a pediatric patient was treated for subclinical hypothyroidism, migraine severity decreased, resulting in a recommendation for pediatricians to test thyroid function as part of the workup for children with migraine.

While none of these studies definitively shows that migraines cause hypothyroidism, there does appear to be a strong predisposition for those with migraine disorder to develop the condition. Alternatively, patients with hypothyroidism often suffer migraines and headaches due to this condition.

What Is the Connection between Migraines and Hypothyroidism?

Hypothyroid symptoms tend to cascade from metabolic effects to brain function, and finally to hormone regulation. One of the most common symptoms of hypothyroidism is a headache.

While there is still some question as to whether hypothyroidism causes headaches or is only a simple link, others believe a history of headaches and migraines can cause an individual to develop hypothyroidism.

Since there is a connection between migraines and hormone function, there is a likelihood that suffering from migraines can eventually impact the thyroid, a hormone-producing gland.

Another symptom of hypothyroidism is edema, which is the excessive accumulation of fluid in human tissue. Edema is often a prelude to migraines or prolonged headaches, adding another link between the conditions.

Co-Treatment Reduces Migraines as well as Treating Hypothyroidism

Co-treatment of subclinical hypothyroidism and migraines seems to be more effective than treatment of symptomatic hypothyroidism.  Treatment with levothyroxine can significantly reduce the frequency and severity of migraines.

Levothyroxine may not alleviate all migraine and hypothyroid symptoms, but a daily prescription of 50 to 100 milligrams can minimize symptoms of both. In a small-scale study of 45 patients, migraine attacks dropped from 14.68 per month to 1.86 per month.

Unfortunately, the higher doses of levothyroxine required for symptomatic hypothyroidism can actually increase the incidence of headaches or migraines. In cases where this occurs, the migraine or headache may need to be diagnosed and treated as a separate disorder through blood tests and imaging studies.

Replacement medication includes over-the-counter pain relievers, triptans, and ergot medications.

Other treatments helpful for both hypothyroidism, whether subclinical or symptomatic and migraines include stress management and self-care. Migraineurs may be able to reduce their hypothyroidism risk through proactive stress relief since stress exacerbated both conditions.

Without treatment or prevention, frequent migraines or illness can create a feedback loop of stress and sickness, worsening each condition in parallel.

Outdoor walks, guided imagery exercises, hot baths, and gentle yoga have all been shown to help relieve stress. Avoiding certain medications can also lower the risk of developing hypothyroidism.

Amiodarone (for irregular heartbeat), interferon (for tumors and Hepatitis C), and lithium (for depression and bipolar disorder) all have a tendency to induce hypothyroidism.

Migraine patients should report any symptoms of significant weight gain, unexplained fatigue, menstrual irregularities, or unexplained muscle ages to their physician. Thyroid tests should then be ordered to diagnose or rule out thyroid disorders.

Neither migraine nor hypothyroidism is a fatal issue, and there is no need to be alarmed. Stay up to date with migraine research to be an informed patient who collaborates with your physician to create the best quality of life possible.