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Does thyroid cause frequent urination?

Frequent or excessive urination, also called polyuria, is a common symptom that can be caused by a variety of underlying conditions. One potential cause is thyroid disorders like hyperthyroidism or hypothyroidism. In this article, we’ll explore the link between thyroid function and frequent peeing, looking at the potential mechanisms as well as symptoms, diagnosis, and treatments. Keep reading to learn more about how thyroid issues could lead to peeing a lot.

Overview of the thyroid gland

The thyroid gland is a small, butterfly-shaped gland located at the base of the neck. It produces thyroid hormones called triiodothyronine (T3) and thyroxine (T4). These hormones play a vital role in regulating metabolism, heart rate, body temperature, and many other essential bodily functions.

The thyroid is controlled by the pituitary gland, which produces thyroid stimulating hormone (TSH). Normal TSH levels tell the thyroid gland to release the right amount of T3 and T4. An imbalance in these hormones leads to thyroid disorders.


Hypothyroidism results when the thyroid gland does not produce enough thyroid hormones. Common causes include Hashimoto’s thyroiditis (an autoimmune disorder), thyroid surgery, radioactive iodine treatment, and certain medications.

In hypothyroidism, TSH levels are elevated because the pituitary gland is attempting to stimulate more hormone production from the underactive thyroid.


Hyperthyroidism occurs when the thyroid is overactive and produces excessive thyroid hormones. Graves’ disease, an autoimmune disorder, is the most common cause. Nodules on the thyroid, thyroid inflammation, or excessive iodine intake can also cause hyperthyroidism.

In hyperthyroidism, TSH levels are low because the thyroid is already overproducing hormones.

Can thyroid disorders lead to frequent urination?

So can imbalances in thyroid hormone levels result in peeing a lot? Research shows that both excessive and insufficient thyroid hormones can increase urinary frequency and output.

Mechanisms linking thyroid and frequent urination

There are a few potential explanations for why thyroid disorders may contribute to frequent peeing:

  • Thyroid hormones directly impact kidney function and urine production. Excess thyroid hormone increases kidney blood flow and filtration rate, while inadequate thyroid hormone slows kidney function.
  • Thyroid disorders can cause excess water intake (polydipsia). Drinking more fluids increases urinary output.
  • Hyperthyroidism causes resting tremors, anxiety, and insomnia which can indirectly increase urine production.
  • Hypothyroidism is linked to impaired release of vasopressin, an antidiuretic hormone that helps regulate urine volume.

So in summary, the thyroid has direct and indirect effects on urinary mechanisms that can alter urinary frequency and volume.


Let’s take a look at some specific symptoms that signal an overactive or underactive thyroid may be causing frequent peeing:


  • Frequent and large urination volumes
  • Increased thirst and fluid intake
  • Restlessness, tremors, heart palpitations
  • Insomnia and anxiety
  • Fatigue despite increased appetite
  • Weight loss
  • Muscle weakness
  • Vision changes


  • Frequent urination
  • Fatigue and lethargy
  • Muscle aches and pains
  • Feeling cold
  • Constipation
  • Dry skin
  • Unexplained weight gain
  • Slower heart rate

Keep in mind that increased thirst and frequent urination can also be caused by uncontrolled diabetes. Other symptoms like dry skin and constipation may help distinguish between diabetes and hypothyroidism.


If you are experiencing frequent urination along with other concerning symptoms, see your doctor. They will perform a medical history, physical exam, and order lab tests to investigate potential causes like thyroid disorders.

Medical history

Your doctor will ask detailed questions about your symptoms, including:

  • How often do you pee during the day and night?
  • Have you experienced increased thirst and drinking?
  • Any other symptoms like fatigue, temperature sensitivity, heart palpitations, tremors, weight changes?
  • What medications are you currently taking?
  • Do you have any other medical conditions?
  • Has anyone in your family been diagnosed with thyroid disorders?

Providing complete and accurate information will help your doctor evaluate whether thyroid dysfunction could be causing frequent urination.

Physical exam

During the physical exam, your doctor will check for signs of hyperthyroidism or hypothyroidism, including:

  • Enlarged thyroid gland
  • Rapid or irregular heart rate
  • Tremors in the hands
  • Dry skin and hair
  • Signs of weight loss or gain

Lab tests

Your doctor will likely order lab tests to measure levels of thyroid hormones including:

  • TSH: Elevated TSH indicates hypothyroidism, while low TSH is seen in hyperthyroidism.
  • Free T4: Measures circulating levels of thyroxine. High T4 levels confirm hyperthyroidism.
  • Free T3: Evaluates triiodothyronine levels. May be elevated in hyperthyroidism.
  • Thyroid antibodies: Presence of antibodies signals autoimmune thyroid disorders like Graves’ disease or Hashimoto’s thyroiditis.

In some cases, imaging like an ultrasound or thyroid scan may also be recommended. These tests allow your doctor to visualize the thyroid gland.


If thyroid disease is diagnosed, getting your hormone levels regulated with treatment can help minimize symptoms like frequent peeing.

Hyperthyroidism treatments

Treatment options for hyperthyroidism include:

  • Antithyroid medications: Methimazole and propylthiouracil work by blocking thyroid hormone production. They help restore normal hormone levels.
  • Radioactive iodine: This oral medication is absorbed by the thyroid. The effects gradually destroy thyroid cells and prevent excess hormone release. Most patients eventually develop permanent hypothyroidism and require thyroid hormone replacement.
  • Surgery: Removing all or part of the thyroid gland is an option if other treatments are not effective. This leads to lifelong hypothyroidism requiring daily thyroid hormone supplementation.

Symptoms like frequent urination generally improve once thyroid hormone levels are stabilized.

Hypothyroidism treatments

Hypothyroidism is treated with synthetic thyroid hormone medication:

  • Levothyroxine: This oral tablet supplement provides the T4 hormone your body needs. The starting dose is adjusted based on factors like age, health status, and TSH levels. Most people require 1.6-1.8 mcg per kilogram of body weight.
  • Liothyronine: This synthetic T3 hormone may be used alone or added to levothyroxine therapy in some cases.

Thyroid hormone replacement helps normalize thyroid function and relieve associated urinary symptoms. Regular monitoring of TSH and thyroid hormone levels is important to ensure the dosage is adequate.

Lifestyle changes like staying well hydrated, limiting caffeine and alcohol, and practicing stress management techniques can also help minimize frequent urination.


In summary, there is a clear link between thyroid disorders and increased urinary frequency and volume. Both hypothyroidism and hyperthyroidism can lead to excessive peeing due to the thyroid’s effects on kidney function, fluid intake, and hormones regulating urine production.

If you are experiencing persistent frequent urination along with other thyroid-related symptoms, see your doctor. Proper testing and diagnosis of any thyroid dysfunction, followed by tailored treatment to restore hormone balance, can help resolve troublesome urinary symptoms. Stay tuned for more helpful health and medical information.