Hearing your heartbeat in your ears is commonly due to a condition called pulsatile tinnitus. This occurs when you perceive a rhythmic thumping or whooshing sound in one or both ears that aligns with your heartbeat. It happens because of turbulent or amplified blood flow in nearby blood vessels, such as arteries and veins near the ears or in the head and neck region. Several factors can cause this phenomenon:

• Vascular conditions like atherosclerosis (narrowing or plaque buildup in arteries) leading to turbulent blood flow.
• High blood pressure which increases blood flow turbulence.
• Malformations or abnormalities in blood vessels near the ear, including aneurysms, arteriovenous malformations, or tangles of blood vessels.
• Abnormalities in the bones near the ear, such as thinning or missing parts of the bony canal in the inner ear (e.g., semicircular canal dehiscence syndrome), allowing internal sounds like heartbeat or blood flow to be heard more clearly.
• Other causes include increased blood flow from anemia, exercise, or thyroid issues, or conductive hearing loss amplifying internal sounds like blood flow.

Most times, pulsatile tinnitus is not a sign of a serious condition, but it can sometimes indicate underlying health issues requiring medical evaluation, especially if persistent or bothersome. A thorough medical examination, possibly including ear examination, hearing tests, and imaging of blood vessels, is often needed to determine the exact cause.

In summary, hearing your heartbeat in your ears is due to hearing amplified or turbulent blood flow sounds in vessels near the ears, a phenomenon known as pulsatile tinnitus.