Updated April 21, 2015.

You may be surprised to know that there is a headache disorder associated with thyroid disease, and having an underactive thyroid may make your headaches— especially migraines— worse.

Let's take a closer look at the thyroid and headache connection and what it means for you.

What is Hypothyroidism?

Hypothyroidism refers to an underactive thyroid gland. The thyroid gland, a butterfly-shaped gland located at the front of the neck, produces and releases thyroid hormone—which controls the body's metabolism or how the body uses energy.

There are a number of causes of hypothyroidism. Hashimoto's autoimmune thyroiditis is the most common cause of hypothyroidism and is caused by the body's immune system producing a reaction against the thyroid.

What are the Symptoms of Hypothyroidism?

In the early stages of hypothyroidism, a person may experience few to no symptoms. But as the disease progresses and the body's metabolic functions slow down, a number of symptoms may appear.

According to the American Association of Clinical Endocrinologists (AACE), here are some symptoms of hypothyroidism:

• Pervasive fatigue and drowsiness
• Forgetfulness and difficulty with learning
• Dry. brittle hair and nails
• Dry, itchy skin
• Puffy face
• Constipation
• Sore muscles
• Weight gain and fluid retention
• Heavy and/or irregular menstrual flow
• Increased frequency of miscarriages
• Increased sensitivity to medications

How is a Headache from Hypothyroidism Diagnosed?

According to the second edition of the International Classification of Headache Disorders (ICHD-II), symptoms of a "headache attributed to hypothyroidism" must develop within 2 months after other symptoms of hypothyroidism become evident and must resolve within 2 months after effective treatment of the hypothyroid state.

The headache must have at least one of the following characteristics:

• bilateral (both sides of the head)
• non-pulsatile (non-throbbing)
• continuous

A headache attributed to hypothyroidism is not associated with nausea or vomiting.

What is the Link Between Hypothyroidism and Headaches?

Approximately 30% of patients with hypothyroidism also suffer from headaches. Also, there is a female preponderance and often a history of migraine in childhood. The precise connection linking these medical conditions is unclear.

Hypothyroidism may also serve as a risk factor for the transformation from episodic to chronic migraine, although this relationship is likely complex and still unclear.

Finally, in the presence of hypothyroidism, headache can be a manifestation of pituitary tumor. Your doctor will order an MRI of the pituitary gland in your brain if he is concerned about this.

The Big Picture

It is not uncommon for people who suffer from hypothyroidism to also have a headache disorder, and treatment of the underactive thyroid  may improve headache control.

Remember, remain proactive in your healthcare. Discuss your symptoms with your healthcare provider, even if you do not think they are relevant. You might be surprised to hear your doctor say that you are not alone, and that he has heard these same symptoms or concerns from other patients.

<sub>Sources

American Association of Clinical Endocrinologists: Hypothyrodism. Accessed April 19th 2015.

Bigal ME, Sheftell FD, Rapport AM, Tepper SJ, Lipton RB. Chronic daily headache: identification of factors associated with induction and transformation. Headache. 2002 Jul-Aug;42(7):575-81.

Headache Classification Subcommittee of the International Headache Society. "The International Classification of Headache Disorders: 2nd Edition". Cephalalgia. 2004;24 Suppl 1:9-160.

Lagman-Bartolome AM, Gladstone J. Metabolic headaches. Neurol Clin. 2014 May;32(2):451-69.

Moreau T, Manceau E, Giroud-Baleydier F, Dumas R, Giroud M. Headache in hypothyroidism. Prevalence and outcome under thyroid hormone therapy. Cephalalgia. 1998 Dec;18(10): 687-89.

Nussey S, Whitehead S. Endocrinology: An Integrated Approach. Chapter 3 The thyroid gland. Oxford: BIOS Scientific Publishers;2001. 

Tepper DE, Tepper SJ, Sheftell FD, Bigal ME. Headache attributed to hypothyroidism. Curr Pain Headache Rep. Aug;11(4):304-9.</sub>

DISCLAIMER: The information in this site is for educational purposes only. It should not be used as a substitute for personal care by a licensed physician. Please see your doctor for diagnosis and treatment of any concerning symptoms or medical condition.