Hearing a rhythmic sound in your ear that beats in synchronization with your pulse can be unsettling, especially when it becomes louder or more noticeable only after you lie down. This symptom, often described as a whooshing, thumping, or buzzing sound, is a perception of internal body noise, not an external sound. While the sound itself may be benign, its presence warrants a professional medical evaluation. The sound is directly related to blood flow dynamics in the vessels near the inner ear, indicating an underlying change in the body’s vascular or pressure systems.
Understanding Pulsatile Tinnitus
The formal name for this condition is pulsatile tinnitus. It is a specific subtype of tinnitus that is objective because it corresponds to the heartbeat, confirming the sound originates from the circulatory system. The sound is produced when blood flow becomes turbulent rather than smooth, often occurring in the carotid artery, jugular vein, or smaller vessels near the ear structures. When blood encounters a narrowing, obstruction, or abnormally high flow, the resulting turbulence creates a noise that the inner ear perceives.
Why Position Affects the Sound
The pulsing is often exacerbated when lying down due to changes in the body’s fluid dynamics and pressure systems. Moving from an upright to a horizontal position means gravity no longer assists the drainage of blood and cerebrospinal fluid from the head. This change in posture alters hemodynamics within the head and neck. Lying flat can increase intracranial pressure (ICP) because blood and fluid distribution equalizes across the body. This increased pressure affects the flow of blood through large veins, such as the jugular vein, increasing the volume and turbulence of blood flow near the ear.
Identifying Underlying Medical Conditions
Pulsatile tinnitus is often a symptom of an underlying medical condition that alters blood flow. Conditions are broadly categorized as those causing high-flow states, those involving vascular structural changes, or those related to bony defects.
High-Flow States
One category involves high-flow states, such as significant anemia or an overactive thyroid gland (hyperthyroidism). These conditions increase the speed and volume of blood circulating throughout the body, making the sound of blood flow louder.
Vascular and Structural Issues
Structural issues within the blood vessels, particularly the arteries, can also be a cause. Atherosclerosis, or the hardening of the arteries, creates irregular inner surfaces in vessels like the carotid artery, leading to turbulent blood flow and an audible whooshing sound. Venous problems, such as a narrowing of the large venous sinuses in the brain, often present as pulsatile tinnitus that is louder when lying down. Rarely, the condition can be caused by vascular masses near the ear or by a congenital thinning of the bone that normally separates the ear canal from large vessels.
Idiopathic Intracranial Hypertension (IIH)
Idiopathic Intracranial Hypertension (IIH) is a significant cause often worsened by lying down. This disorder is characterized by elevated pressure of the fluid surrounding the brain and spinal cord. IIH is frequently associated with venous sinus stenosis, where the high pressure in the head partially compresses the drainage veins, creating turbulence.
Diagnosis and Management Options
The investigation begins with a detailed medical history and a physical examination. The physician uses a specialized stethoscope to listen for a vascular murmur, or “bruit,” over the ear or neck. Applying gentle pressure to the jugular vein can help determine if the cause is venous, as the sound may temporarily stop. Blood tests are often ordered to check for high-flow conditions like anemia or thyroid disorders.
Imaging studies are typically required to visualize the blood vessels and surrounding structures in the head and neck. Specialized scans like Magnetic Resonance Angiography (MRA) or Computed Tomography Angiography (CTA) map the arteries, while Magnetic Resonance Venography (MRV) or CT Venography highlights the veins. These modalities help identify narrowings, structural defects, or vascular malformations. Management is directed entirely at the underlying cause, which may involve medication, treatment for thyroid dysfunction, or surgical procedures to correct vascular abnormalities or bony defects. Prompt medical attention is advised, especially if the pulsing sound is sudden, constant, or accompanied by other symptoms like headaches or changes in vision.