The experience of hearing a rhythmic sound in the ear that syncs precisely with a person’s heartbeat is medically known as pulsatile tinnitus (PT). Unlike the more common form of tinnitus, which involves non-rhythmic ringing or buzzing, PT is a physical sound generated within the body’s circulatory system. This sound is often described as a whooshing, thumping, or pulsing noise. The occurrence of this symptom specifically in the left ear suggests a localized issue or an anatomical variation on that side, making a medical evaluation necessary to determine the source.
Understanding Pulsatile Tinnitus
Pulsatile tinnitus originates from blood flow becoming audible due to its proximity to the auditory system. The ear structures are situated in the temporal bone, which houses major blood vessels. Normally, the sound of blood moving through these vessels is dampened by surrounding tissues and bone, making it inaudible.
The perception of this pulse-synchronous sound occurs when blood flow becomes turbulent or when the natural sound insulation around the ear fails. Turbulent flow, often described as a whooshing sound, is created by irregularities in the vessel wall or by blood moving too quickly. Amplification of the sound often results from a defect in the bone structure, such as a thin section of the temporal bone, allowing the noise to transmit directly to the cochlea.
PT can arise from issues involving both arteries and veins. The unilateral presentation, such as in the left ear, often points toward a structural cause or a localized anatomical anomaly on that side. Even if the underlying cause is systemic, a difference in the left-side anatomy, such as a high-riding jugular bulb, can make the sound more noticeable in that specific ear.
Transient Reasons for Increased Blood Flow
Not every instance of hearing one’s pulse signals a long-term problem, as many occurrences are temporary and benign. These transient causes relate to an increase in the heart’s output, which temporarily elevates the speed and volume of blood flow. Strenuous physical activity or emotional states like high stress trigger adrenaline release, causing the heart to beat faster and stronger. This temporary hyperdynamic circulation results in brief audible pulsing that resolves once the body returns to a relaxed state.
Other physiological conditions that increase cardiac output, such as severe anemia or hyperthyroidism, can also lead to temporary or persistent pulsatile noise. Furthermore, simple changes within the ear can reduce the natural damping of internal sounds. A temporary buildup of earwax or fluid accumulation from a cold can create conductive hearing loss, which effectively amplifies internal body noises and makes blood flow more noticeable.
Systemic and Structural Causes Requiring Intervention
Persistent pulsatile tinnitus often points to a chronic issue requiring medical evaluation and potential intervention. These causes are typically grouped into problems related to the vascular system or those involving pressure regulation in the head. Vascular problems involve changes in blood vessel structure that create turbulent, noisy flow.
Systemic conditions that increase flow force or restrict vessels include high blood pressure (hypertension), which forces blood through vessels with greater force, increasing audibility. Atherosclerosis, where fatty plaques narrow arteries, causes blood to rush through the restricted space. Arterial issues can also include dural arteriovenous fistulas (DAVFs), which are abnormal connections between arteries and veins resulting in high-flow turbulence near the ear.
Venous issues often involve the large veins that drain blood from the brain, such as the transverse and sigmoid sinuses. Conditions like venous sinus stenosis, a narrowing of these large veins, disrupt smooth blood flow and generate the pulsing sound. Structural anomalies, such as a sigmoid sinus diverticulum, can also bring the vessel closer to the ear structures, making the sound readily audible.
A significant category involves conditions that increase pressure around the brain, most commonly Idiopathic Intracranial Hypertension (IIH). IIH involves elevated fluid pressure inside the skull, which can compress the large veins. This compression often leads to venous sinus stenosis and audible, turbulent flow, frequently manifesting alongside symptoms like headache and vision changes.
The Diagnostic Process and Treatment Options
A medical investigation for pulsatile tinnitus begins with a comprehensive physical examination, including auscultation. The doctor listens over the ear, neck, and mastoid area using a stethoscope to determine if the sound is objective, meaning it can be heard by the examiner. Changing the sound with gentle compression of the jugular vein in the neck can strongly suggest a venous origin.
Diagnostic imaging is often necessary to visualize the blood vessels and surrounding structures. Magnetic Resonance Angiography (MRA) and Magnetic Resonance Venography (MRV) are preferred non-invasive tests to evaluate arterial and venous problems, respectively. These specialized scans help identify vessel narrowing, structural anomalies, or the presence of vascular masses near the ear.
Treatment is entirely dependent on the underlying cause identified through the diagnostic workup. If the cause is a systemic issue like hypertension, treatment focuses on medication and lifestyle changes to lower blood pressure. For structural abnormalities, such as venous sinus stenosis related to IIH, treatment may involve medication to reduce intracranial pressure or the placement of a stent to widen the narrowed vein.
If a tumor, such as a glomus tumor, is found, treatment can involve surgical removal or radiation therapy. Addressing the root cause successfully eliminates the pulsatile noise in many cases. Even when no specific cause is found, management often includes sound therapy or behavioral techniques to reduce the perception and impact of the sound.