How Does Hypothyroidism Affect Your Menstrual Cycle?

There are many symptoms of hypothyroidism, and irregular periods can be one of them. Read on to find out how thyroid issues can affect your menstrual cycle.

By OBGYN Dr. Kenosha Gleaton

Hypothyroidism is seen in about 5% of Americans and can impact many different bodily functions, including the menstrual cycle and fertility. [1-2]. Let’s talk about what hypothyroidism is, what symptoms to look out for, and how it can impact the menstrual cycle. 

What is hypothyroidism?

Hypothyroidism is a condition related to the thyroid gland and is characterized by having an underactive thyroid [1]. The thyroid is a butterfly shaped gland located in the front of the neck. The thyroid is responsible for releasing hormones that impact nearly every organ in the body and play a role in our metabolism, growth, and development [1]. When someone has hypothyroidism, their thyroid is underperforming and not producing enough thyroid hormone. This can be diagnosed through a medical history as well as imaging tests and blood tests. Hypothyroidism may cause various symptoms and may lead to health complications if left untreated [1]. 

What causes it?

Hypothyroidism has several causes, including [1-2]:

• Hashimoto’s disease—an autoimmune disorder 

• Inflamed thyroid— a result of other disorders, antibodies, bacteria, and more

• Congenital hypothyroidism, or hypothyroidism that is present at birth

• Iodine deficiency (rare in the United States)

• Surgical removal of part or all of the thyroid

• Radiation treatment of the neck/head 

• Some medicines, such as heart medicines, cancer medicines, and medicines to treat bipolar disorder

Symptoms of hypothyroidism

When your body isn’t making enough thyroid hormone, different systems slow down and may cause noticeable signs and symptoms. These include [1]: 

• Fatigue

• Weight gain

• Muscle and joint pain

• Depression

• Decreased heart rate

• Sensitivity to cold

• Dry skin or dry, thinning hair

• Heavy or irregular menstrual periods or fertility problems

• Increased cholesterol

Hypothyroidism usually develops slowly, so symptoms may not arise for months or even years. Symptoms are also frequently mild. Some symptoms of hypothyroidism are common symptoms of other conditions, medications, and aging and don't necessarily mean you have a thyroid condition. 

Who is at risk of hypothyroidism?

People over the age of 60 and those assigned female at birth are at the highest risk of developing hypothyroidism. The American Thyroid Association recommends that screening for hypothyroidism begin around age 35 and continue every five years [2]. Some populations are at an especially high risk, including [2]:

• People assigned female at birth over the age of 60

• Pregnant individuals

• Those with a history of head and neck irradiation (radiation therapy)

• Those with autoimmune disorders, including Hashimoto disease

• Those with type 1 diabetes

• Individuals with thyroid peroxidase antibodies (commonly seen in Hashimoto patients)

• Those with a family history of thyroid condition

How to manage hypothyroidism

General treatment and management of hypothyroidism consists of hormone replacement. Since the thyroid is struggling to make higher levels of hormones, patients often take levothyroxine, a prescription medication taken orally that is identical to the hormone a healthy thyroid makes [1]. Dose will vary from person to person and will be decided after blood tests are examined. As long as the recommended medications are taken, hypothyroidism can be controlled easily with long-term management [1]. Learn more about how to fix hormonal imbalances. 

How does hypothyroidism impact menstruation?

The thyroid and thyroid hormones impact all physiological activities in humans, including menstruation [3]. Hypothyroidism may lead to delayed menstruation or oligomenorrhea (infrequent periods) due to the connection between various hormones. Vital hormones such as thyrotropin-releasing hormone (TRH), thyroid-stimulating hormone (TSH), thyroxine (T4), and triiodothyronine (T3) are abnormally high or low in those with hypothyroidism; this has a direct effect on reproductive hormones such as prolactin, gonadotropin-releasing hormone, and globulin [3]. 

That’s a lot of information and a lot of hormone names, but the gist is this: hypothyroidism’s effect on various hormones can impact menstruation and even fertility. There are associations between hypothyroidism and altered ovulatory function, irregular menstrual cycles, subfertility, and recurrent miscarriage [4]. A study found that in patients with menstrual disorders, 44% had thyroid conditions, including hypothyroidism (34%) and hyperthyroidism (8%) [5] . 

If you have been diagnosed with a thyroid condition or are concerned you may have one, menstrual cycle irregularities and infertility may be two symptoms of hypothyroidism. 

Hypothyroidism and fertility

Thyroid conditions may impact fertility similarly to how they impact the menstrual cycle. Irregular hormone levels interacting with other hormones may lead to decreased ovulatory function, difficulty getting pregnant, recurrent miscarriages, and more [4]. With the proper treatment, many are still able to get pregnant and carry a healthy pregnancy. A study found that 76% of women struggling to conceive due to hypothyroidism were able to conceive within a year of starting thyroid medication [7]. 

If you are hoping to conceive with a thyroid condition and have had trouble with regular menstrual cycles or regular ovulation, you may be a good candidate for ovulation induction. Speak with your healthcare provider about your options for fertility treatments while taking your medication.  

Regulating menstrual cycles with hypothyroidism

If you’re hoping for regular menstrual cycles and you do have hypothyroidism, be sure you talk to your healthcare provider about your prescribed levothyroxine dose. Taking this medication should help to regulate your hormones and may result in regular menstrual cycles. If you’re still having irregular cycles, there are some other options you can explore as well.

If you aren’t trying to conceive, hormonal contraceptives may help regulate your menstrual cycle. You need to speak with your healthcare provider directly about when and how much to take, but in general, you can take hormonal contraceptives while taking thyroid medication. You may just need to wait a few hours between pills. 

Other lifestyle factors such as high stress, physical activity, etc. can have an effect on your cycle regularity. Try to find healthy ways to manage stress, and make sure you are eating and exercising within your healthy limits. You may want to consider supplements such as inositol as well, which has been shown to support ovulatory function and cycle regularity [6]. 

You should always speak with your healthcare provider directly about any medical concerns, including the use of any medications or supplements alone or in combination with prescription drugs.

Key Takeaways

• Hypothyroidism is a condition that’s characterized by having an underactive thyroid. 

• The thyroid is responsible for releasing and regulating hormones in the body that impact many bodily functions, including reproductive health. 

• Many factors may cause hypothyroidism, including radiation therapy of the neck or head, Hashimoto’s disease, surgical removal of the thyroid, and more. 

• Some symptoms of hypothyroidism include weight gain, fatigue, sensitivity to cold, depression, and more. Not everyone will experience symptoms, and often symptom onset is very slow. 

• The people at the highest risk of developing hypothyroidism are people assigned female at birth and those over the age of 60. 

• When untreated, it’s not uncommon for hypothyroidism to cause delayed and infrequent menstruation. 

• Getting proper treatment in the form of hormone replacement therapy is a great way to manage hypothyroidism and may help regulate the menstrual cycle and ovulation. 

• It is possible to have regular menstrual cycles and get pregnant with hypothyroidism, but talk to your healthcare provider if you are hoping to conceive soon.

References:

1. Hypothyroidism (Underactive Thyroid). National Institutes of Diabetes and Digestive and Kidney Diseases. Reviewed March 2021. Accessed March 2023. URL. 
2. Patil N, Rehman A, Jialal I. Hypothyroidism. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. URL. 
3. Ukibe NR, Ukibe SN, Emelumadu OF, et al. Impact of thyroid function abnormalities on reproductive hormones during menstrual cycle in premenopausal HIV infected females at NAUTH, Nnewi, Nigeria. PLoS One. 2017;12(7):e0176361. Published 2017 Jul 19. doi:10.1371/journal.pone.0176361
4. Saran S, Gupta BS, Philip R, et al. Effect of hypothyroidism on female reproductive hormones. Indian J Endocrinol Metab. 2016;20(1):108-113. doi:10.4103/2230-8210.172245
5. Ajmani NS, Sarbhai V, Yadav N, Paul M, Ahmad A, Ajmani AK. Role of Thyroid Dysfunction in Patients with Menstrual Disorders in Tertiary Care Center of Walled City of Delhi. J Obstet Gynaecol India. 2016;66(2):115-119. doi:10.1007/s13224-014-0650-0
6. Kachhawa G, Senthil Kumar KV, Kulshrestha V, Khadgawat R, Mahey R, Bhatla N. Efficacy of myo-inositol and d-chiro-inositol combination on menstrual cycle regulation and improving insulin resistance in young women with polycystic ovary syndrome: A randomized open-label study. Int J Gynaecol Obstet. 2022;158(2):278-284. doi:10.1002/ijgo.13971
7. Verma I, Sood R, Juneja S, Kaur S. Prevalence of hypothyroidism in infertile women and evaluation of response of treatment for hypothyroidism on infertility. Int J Appl Basic Med Res. 2012;2(1):17-19. doi:10.4103/2229-516X.96795
8. Mobeen S, Apostol R. Ovarian Cyst. In: StatPearls. Treasure Island (FL): StatPearls Publishing; June 13, 2022.