Hypothyroidism and Tinnitus: What’s the Connection?

Hypothyroidism raises the risk of tinnitus, and the connection is stronger than many people realize. A large population-based study found that people with hypothyroidism developed tinnitus at roughly 1.5 times the rate of those without the condition, even after accounting for other health factors. The link runs through several biological pathways, from direct effects on the delicate hair cells of the inner ear to changes in fluid balance and nerve signaling that can generate or amplify phantom sounds.

How Much More Common Is Tinnitus in People With Hypothyroidism

The clearest population-level evidence comes from a Taiwanese cohort study that followed tens of thousands of people over time. Tinnitus developed at a rate of about 9.5 per 1,000 person-years in the hypothyroidism group, compared to roughly 6 per 1,000 person-years in matched controls. After adjusting for age, sex, and other conditions that could muddy the picture, hypothyroidism was associated with about a 35% higher risk of developing tinnitus.¹

A separate study focusing specifically on annoying tinnitus (the kind that actually bothers people, not just occasional ringing they can ignore) found that women with low thyroid-stimulating hormone levels had more than twice the odds of experiencing it. That association held even when free thyroxine levels looked normal on a blood test, suggesting the relationship is not limited to full-blown thyroid failure.²

Brazilian researchers examining patients with acquired hypothyroidism reported that about 17% had tinnitus, compared to a lower rate in the control group. Hearing loss was even more common, turning up in over a third of the ears tested among hypothyroid patients.³

Why Thyroid Hormones Matter to the Inner Ear

The inner ear is not just passively affected when thyroid levels drop. It is an active target of thyroid hormones, packed with receptors that respond to them directly. Research on rat cochleae has shown strong staining for thyroid hormone receptors in the spiral ganglion cells (the neurons that relay sound signals to the brain) and in both inner and outer hair cells, the tiny structures that convert sound vibrations into electrical signals.⁴ When thyroid hormone is missing, these receptors sit empty, and the cells they regulate do not develop or function properly.

One of the key downstream effects involves a specific type of thyroid receptor called TRβ. Loss of TRβ function impairs a potassium channel in inner hair cells that is needed for normal hearing. Without this channel working correctly, the electrical signaling that hair cells use to communicate with nerve fibers goes haywire. Mice lacking TRβ are deaf, and mutations in the same receptor gene cause hearing loss in humans.⁵

Recent work on lab-grown human cochlear tissue has shown that adding thyroxine (the main thyroid hormone) accelerates the maturation of outer hair cells and drives expression of prestin, the protein that gives outer hair cells their ability to change shape in response to sound. Outer hair cells treated with thyroxine displayed electromotility, the active vibration that amplifies quiet sounds and sharpens frequency tuning. Without adequate thyroid hormone, these cells remain immature and less functional.⁶

Thyroid hormones also regulate the sodium-potassium pump (Na,K-ATPase) in several regions of the cochlea, including the stria vascularis, which maintains the ion-rich fluid environment that hair cells need to function. In hypothyroid animals, the activity of both the alpha-1 and beta-1 pump variants drops in these regions within a few weeks.⁷ The stria vascularis is essentially the battery of the inner ear. When its pump slows down, the electrochemical gradient that powers hair cell signaling weakens, and the conditions for abnormal neural firing that can be perceived as tinnitus start to build.

Fluid Buildup in the Inner Ear

One of the more dramatic findings in animal research is that thyroid hormone deficiency can trigger endolymphatic hydrops, an abnormal accumulation of fluid inside the inner ear. In a rat model, every single thyroidectomized animal developed hydrops, while none of the controls did. The swelling affected Reissner’s membrane, the vestibular system, the stria vascularis, and the utricular macula, with severity varying across individuals.⁸

Endolymphatic hydrops is also the hallmark pathology of Ménière’s disease, which features episodic tinnitus, hearing loss, and vertigo. The overlap raises an interesting question about how many patients diagnosed with Ménière’s-like symptoms actually have an underactive thyroid contributing to or causing their fluid imbalance. It also explains why some hypothyroid patients report not just ringing in the ears but also a sensation of ear fullness or dizziness, since the excess fluid distorts signaling in both the hearing and balance organs.

Slowed Signals Along the Auditory Nerve

Beyond the inner ear itself, hypothyroidism appears to slow the transmission of sound signals through the brainstem. Several studies using brainstem auditory evoked potentials (a test that measures how quickly electrical signals travel from the ear to the brain) have found consistent delays in hypothyroid patients.

In patients with clinical hypothyroidism, the later waves of the brainstem response, which reflect processing at higher levels of the auditory pathway, were significantly prolonged compared to controls. The time between early and late waves was also stretched, pointing to a slowdown at the brainstem and midbrain levels rather than just at the ear.⁹ These delays matter for tinnitus because the brainstem is one of the key sites where the brain processes and filters auditory input. When signaling there becomes sluggish or disorganized, the brain may compensate by turning up its internal “gain,” which can amplify neural noise into a perceived sound.

This is not limited to people with severe thyroid problems. Even subclinical hypothyroidism, where TSH is elevated but thyroid hormone levels remain in the normal range, produced similar delays in brainstem waves III and V, along with stretched intervals between peaks.¹⁰ A separate study of women with subclinical hypothyroidism confirmed the same pattern of prolonged absolute latencies for waves I, III, and V and increased interpeak latencies.¹¹

The Brazilian audiological study found similar results. Mean wave V latencies were significantly higher in the hypothyroid group, and otoacoustic emissions (sounds generated by healthy outer hair cells) were absent in 20% of hypothyroid patients compared to about 7% of controls. When both the brainstem pathway and the hair cells themselves show dysfunction, the conditions for tinnitus stack up from two directions at once.³

The Autoimmune Angle

Hashimoto’s thyroiditis, the most common cause of hypothyroidism in developed countries, introduces a separate mechanism that has nothing to do with low hormone levels. Because Hashimoto’s is an autoimmune condition, the immune system produces antibodies that attack thyroid tissue. Evidence suggests those same autoantibodies, or the immune response they set off, can also damage the inner ear.

Case reports and literature reviews have documented autoimmune inner ear disease developing alongside Hashimoto’s. The proposed mechanism involves circulating antithyroid antibodies triggering T-cell-mediated damage to cochlear and vestibular structures. Researchers reviewing these cases have argued that a clear relationship exists between thyroid autoimmunity and inner ear damage, and that this relationship can occur regardless of whether the patient’s thyroid hormone levels have actually dropped yet.¹²

This is clinically important because it means a person with Hashimoto’s could develop tinnitus or hearing loss even before their blood tests show low thyroid hormone. If you have Hashimoto’s and notice changes in your hearing or new ringing in your ears, the autoimmune process itself, not just the hormone deficiency, could be driving the problem. It also means that simply correcting thyroid hormone levels with medication may not fully resolve ear symptoms if immune-mediated damage is ongoing.

Does Treating Hypothyroidism Help the Tinnitus

The encouraging news is that treating hypothyroidism appears to improve auditory function in a meaningful number of patients, though the response is not guaranteed. In one study evaluating hypothyroid patients before and after thyroxine replacement therapy, hearing thresholds improved significantly in about 46% of ears tested. Brainstem auditory response wave amplitudes also improved with treatment.¹³

That roughly 46% figure means more than half of the ears tested did not show clear improvement, which underscores that the damage from hypothyroidism is not always reversible. Several factors likely influence who recovers and who does not. How long the thyroid condition went untreated matters, because prolonged hormone deficiency gives the inner ear’s ion balance, hair cells, and nerve pathways more time to deteriorate. The severity of the deficiency also plays a role, as does whether autoimmune damage to the cochlea occurred independently of the hormone issue.

Reduced cell energy production from hypothyroidism impairs microcirculation, which affects oxygenation and metabolism in the inner ear.¹⁴ If blood flow to the cochlea has been compromised for a long time, some structural changes may become permanent. The practical takeaway is that early detection and treatment of hypothyroidism give you the best chance of preventing or reversing ear symptoms, but restoring hormone levels later in the course of disease still helps a substantial proportion of patients.

Subclinical Hypothyroidism Is Not Benign for Your Ears

One of the most practically relevant findings in this area is that you do not need full-blown hypothyroidism to experience auditory effects. Subclinical hypothyroidism, where TSH is elevated but circulating thyroid hormones remain within the normal reference range, is far more common than overt hypothyroidism. Many clinicians take a wait-and-see approach to subclinical cases because the hormone levels themselves look acceptable.

But as the brainstem studies described earlier show, auditory nerve signaling is already delayed in subclinical cases.¹⁰ The Korean tinnitus study reinforced this point from a different direction: women whose TSH was low (not just normal, but suppressed) had more than double the odds of bothersome tinnitus, even when their free thyroxine was in the normal range.² Together, these findings suggest the auditory system is more sensitive to thyroid perturbations than standard thyroid screening acknowledges.

If you are being monitored for a borderline thyroid condition and you notice tinnitus, it is worth mentioning the connection to your doctor. The ear symptoms may be an early sign that the subclinical state is already having physiological consequences, which could tip the risk-benefit balance toward starting treatment sooner.

Why Women Seem More Affected

Hypothyroidism itself is far more common in women, so it is no surprise that more research on the thyroid-tinnitus link involves female participants. But the Korean survey data suggests the relationship between thyroid status and bothersome tinnitus may also be genuinely stronger in women. In that analysis, the association between low TSH and annoying tinnitus was apparent in the female subgroup but not in the male subgroup.²

Whether this reflects a true biological sex difference or simply the difficulty of detecting an effect in a much smaller male hypothyroid population is an open question. Estrogen interacts with thyroid hormone signaling in several tissues, and it is plausible that hormonal cross-talk makes the female cochlea more responsive to thyroid fluctuations. For now, though, the practical implication is clearer than the mechanism: women with thyroid problems should be particularly alert to changes in hearing or new tinnitus symptoms.

Conditions That Stack the Risk

Hypothyroidism rarely travels alone. The Taiwanese cohort study that established the 35% increased risk of tinnitus also examined how comorbidities interacted with the thyroid effect. Conditions commonly seen alongside hypothyroidism, including high blood pressure, diabetes, high cholesterol, and depression, each added to the overall tinnitus risk in the hypothyroid group.¹ Several of these conditions also independently affect the inner ear: diabetes damages small blood vessels including those supplying the cochlea, and high blood pressure can impair cochlear blood flow.

This layering effect means that a person with hypothyroidism plus diabetes plus hypertension is at considerably higher risk than someone with hypothyroidism alone. It also means that aggressively managing those comorbidities could help protect hearing even before the thyroid itself is addressed. If you have multiple metabolic conditions and notice tinnitus, it is tempting to blame just one of them, but the evidence points toward a cumulative effect that makes the whole package worse than any individual piece.

When Thyroid Problems Begin Before Birth

The stakes are highest when thyroid hormone is missing during fetal and early postnatal development. In animal models, thyroid deficiency before the onset of hearing causes irreversible damage to both peripheral and central auditory systems. The severity of the hearing deficits increased with each additional day of thyroid hormone deficiency during the critical window before the auditory system comes online.¹⁵

Children with congenital hypothyroidism can develop hearing problems because thyroid hormones are crucial for the auditory pathway’s development and maturation. Hearing impairment at an early age can in turn impair language skills, literacy, and cognitive and social development.¹⁶ Newborn screening programs that detect congenital hypothyroidism and begin treatment within the first weeks of life have been one of the great public health successes of modern pediatrics. But the auditory system’s sensitivity to early thyroid deficiency means that even modest delays in starting treatment can have lasting consequences for hearing that may not become obvious until a child begins learning to speak.

For pregnant women with hypothyroidism, consistent thyroid hormone replacement throughout pregnancy protects fetal ear development. Maternal thyroid hormones cross the placenta and supply the developing baby, especially in the first trimester before the fetal thyroid gland begins functioning on its own. Uncontrolled maternal hypothyroidism during this period can leave the fetal cochlea without the hormonal signals it needs to wire properly, with effects that persist even after thyroid levels are normalized later.

1
PubMed Central. Hypothyroidism and related comorbidities on the risks of developing tinnitus
2
PubMed. Low Thyroid-stimulating Hormone Levels Are Associated With Annoying Tinnitus in Adult Women: Korea National Health and Nutrition Examination Surveys
3
Brazilian Journal of Otorhinolaryngology. Audiologic evaluation in patients with acquired hypothyroidism
4
PubMed. Postnatal expression of the alpha-thyroid hormone receptor in the rat cochlea
5
PubMed. Thyroid hormone receptor beta-dependent expression of a potassium conductance in inner hair cells at the onset of hearing
6
Cell Reports. Thyroid hormone augmentation accelerates hair cell maturation in human cochlear organoids
7
PubMed. Responsiveness of alpha 1 and beta 1 cochlear Na, K-ATPase isoforms to thyroid hormone
8
PubMed Central. Thyroid hormone deficiency induces endolymphatic hydrops: neurological and histopathological evidence from an experimental rat model
9
PubMed Central. Brainstem auditory evoked potential in clinical hypothyroidism
10
PubMed Central. Study of Auditory Brainstem Evoked Response at Varying Frequencies in Subclinical Hypothyroid Subjects
11
PubMed Central. Evaluation of the Female Patients with Subclinical Hypothyroidism by Brainstem Auditory Evoked Potentials: Case-Control Study
12
PubMed Central. Autoimmune inner ear disease secondary to Hashimoto’s thyroiditis: a case report
13
PubMed Central. Audiological Evaluation in Hypothyroid Patients and Effect of Thyroxine Replacement Therapy
14
Annals of Otology and Neurotology. Thyroid Disorders Causing Hearing Loss: A Scoping Review
15
Journal of Neurophysiology. Thyroid hormone deficiency before the onset of hearing causes irreversible damage to peripheral and central auditory systems
16
PubMed Central. Congenital Hypothyroidism and the Deleterious Effects on Auditory Function and Language Skills: A Narrative Review