Ask the Doctors

Dear Doctor: A few months ago, I started to hear pulsating sounds in my head. I finally came to realize it was my blood pulsing. The sound is always there, but really only noticeable when I'm in bed or sitting quietly. Is it anything to worry about? Will it ever go away?

Dear Reader: What you're describing sounds like the symptoms of pulsatile tinnitus. Tinnitus is normally perceived as a ringing, buzzing or whistling sound in the ear. Pulsatile tinnitus, however, is a pulsing sound synchronous to the heartbeat. It occurs in less than 10 percent of people who have tinnitus. I have had patients, and a family member, with pulsatile tinnitus, so I understand how intrusive and irritating the sounds can be, especially when one lies down at night. Usually, this type of tinnitus is heard in just one ear.

The biggest issue with pulsatile tinnitus is finding the source. Often the pulsing sensation is caused by malformations between the arterial system and the venous system and the ensuing turbulent blood flow that occurs when blood moves from a high-pressure system, the artery, to a low-pressure system, the vein.

Pulsatile tinnitus can also occur when the temporal bone transmits the sound of a nearby artery -- or from more serious conditions, such as when a nearby artery suffers an aneurysm, when a carotid artery narrows, or when a person develops a paraganglioma (a tumor that can occur in the neck and in the head). Often, these tumors are located near blood vessels and have a good blood supply, leading to turbulent blood flow that is audible not only to the person but also sometimes the doctor. Elevated blood pressure in the brain and anemia can play a role in pulsatile tinnitus as well.

Due to concerns about aneurysms, malformations, narrowing of the carotid artery and paragangliomas, it is important to try to identify the cause of the pulsatile tinnitus. Diagnostic testing can detect an underlying cause in 70 percent of patients. To get to a diagnosis, your doctor will need to take a thorough history and do a focused examination.

Radiologic tests then may be necessary to find the cause. An MRI of the brain with MR angiography can identify vascular abnormalities and brain tumors. A CT scan with angiography can also identify vascular lesions and tumors, but not as well as an MRI. One differentiating benefit with a CT scan is that it can identify bony lesions near the ear that would lead to pulsatile tinnitus.

So, I wouldn't ignore the sounds you're hearing. You should make an appointment with your primary care doctor or an ear, nose and throat doctor to evaluate the cause of your symptoms. They may recommend imaging to try to identify the cause, as well as treatment for some of the conditions related to pulsatile tinnitus. Then, finally, you may find relief from this irritating symptom.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

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