Hashimoto’s disease is an autoimmune condition where the body’s immune system mistakenly attacks the thyroid gland, which leads to an underactive thyroid, known as hypothyroidism. The thyroid gland produces hormones that regulate metabolism and energy use throughout the body. When the thyroid’s function is compromised, it can cause a wide array of systemic symptoms. Dizziness and balance issues are recognized symptoms that can be traced back to this autoimmune process.
Establishing the Link Between Hashimoto’s and Dizziness
Dizziness is a frequent complaint among patients with autoimmune thyroid disease, though the connection is often indirect. Hashimoto’s disease itself is a primary autoimmune condition, but the resulting state of hypothyroidism is often the source of the dizzy sensation. Hypothyroidism, characterized by low levels of thyroid hormone, affects numerous body systems that control stability and perception.
The link is common enough that vestibular dysfunction, which includes issues with balance and dizziness, is documented in patients with Hashimoto’s. Research highlights that this dysfunction can occur even in patients whose thyroid hormone levels are within the normal range. This suggests that the generalized autoimmune process, rather than solely the low hormone level, contributes to some cases of imbalance.
Systemic Effects Leading to Dizziness
One of the most common ways Hashimoto’s contributes to dizziness is through its effect on the cardiovascular system. Hypothyroidism slows down the body’s overall metabolism, which often results in a slower-than-normal heart rate, known as bradycardia. This reduced cardiac output can lead to diminished blood flow reaching the brain, causing lightheadedness or a faint feeling.
The condition can also contribute to a form of low blood pressure called orthostatic hypotension. When a person stands up quickly, blood can pool in the lower extremities, and the body’s reflexes may be too sluggish to compensate by constricting blood vessels. This drop in blood pressure upon changing posture results in a temporary feeling of unsteadiness or dizziness.
Hypothyroidism sometimes causes anemia, a reduction in the red blood cells needed to transport oxygen. A lack of adequate oxygen delivery to the brain can produce symptoms of lightheadedness and generalized weakness, contributing to a feeling of instability. The profound fatigue and sluggishness that often accompany low thyroid hormone levels can also make a person feel unsteady or off-balance.
Autoimmune Vestibular and Inner Ear Involvement
Beyond systemic effects, the autoimmune nature of Hashimoto’s can directly affect the balance-controlling structures of the inner ear. The inner ear contains the vestibular apparatus, a system that helps regulate balance and spatial orientation. Autoimmune Inner Ear Disease (AIED) is a condition where the immune system attacks these structures, and it is more common in people with other autoimmune diseases like Hashimoto’s.
This direct autoimmune attack may involve cross-reactivity, where the antibodies intended to target the thyroid gland mistakenly attack similar-looking tissues in the inner ear. This can lead to true vertigo, which is the sensation that the room is spinning, as opposed to simple lightheadedness. This attack can also manifest as Benign Paroxysmal Positional Vertigo (BPPV), a specific type of spinning dizziness triggered by head movements, which has been observed to be more prevalent in individuals with Hashimoto’s.
In rare cases, the autoimmune process can affect the central nervous system, leading to a condition called Hashimoto’s encephalopathy. This neurological involvement can cause symptoms like cerebellar ataxia, resulting in severe gait instability and imbalance. The severity of vestibular damage has been linked to higher levels of thyroid peroxidase (TPO) antibodies, suggesting a direct connection between the autoimmune activity and the balance system.
When to Consult a Doctor and Diagnostic Steps
If dizziness or vertigo is a recurring symptom, it warrants a consultation with a healthcare provider, especially if it interferes with daily activities or is accompanied by other neurological symptoms. Symptoms that require immediate medical attention include severe vertigo, fainting, chest pain, or sudden hearing loss, as these can indicate more serious complications.
The initial diagnostic approach involves a thorough review of thyroid function through blood tests, including Thyroid-Stimulating Hormone (TSH) and free T4 levels. Testing for the presence of thyroid antibodies, such as TPO antibodies, is performed to confirm the diagnosis of Hashimoto’s. Other blood work checks for common systemic contributors, such as anemia, which can be a consequence of hypothyroidism.
For dizziness upon standing, a doctor may check for orthostatic hypotension by measuring blood pressure in both lying and standing positions. If the dizziness is characterized by true vertigo or is persistent despite optimized thyroid hormone levels, a referral to an otolaryngologist or neurologist is necessary. These specialists can perform specific vestibular testing, like the Dix-Hallpike maneuver, to determine if the inner ear is directly involved.