Anemia is a condition in which the body has low levels of healthy red blood cells, which are needed to deliver oxygen throughout the body. It’s relatively common; almost 10% of the population has anemia. Some symptoms of anemia include fatigue and dizziness, chest pain, shortness of breath and heart palpitations, and recent research shows a significant correlation between anemia and hearing loss. One study showed that the odds of hearing loss were higher by 55% in individuals with iron-deficiency anemia compared to individuals who were not anemic.
You Need Healthy Blood for Hearing
Let’s review how hearing works first. Sound waves hit the eardrum in the outer ear, causing it to vibrate (much like a drum). The eardrum’s vibrations travel through the middle ear, where they are amplified, into the inner ear to an organ called the cochlea. The cochlea is filled with a fluid (called cochlear fluid) which ripples as the vibrations pass through it. As the fluid ripples, it flows over hair-like cells within the cochlea like waves on a river. These cells wave in the ripples of the cochlear fluid, and this waving sparks electrical signals that your hearing nerve carries to the brain to be interpreted as sound.
Blood flow is very important to this process, because those hair cells need a constant supply of blood and the oxygen it brings to function properly. If they don’t receive sufficient oxygen or blood flow, these hair cells can become permanently damaged, leading to hearing loss. Notably, the cochlea is supplied with blood by only one artery (called the labyrinthine artery), so any restriction to that artery will affect the ear.
Anemia and Hearing Loss
Now that we’ve seen how blood flow works in your auditory system, let’s discuss how anemia can affect it and even cause hearing loss. There are several subtypes of anemia, each impacting the auditory system and hearing slightly differently. Here are some of them.
Iron-Deficiency Anemia
Iron-deficiency anemia, or IDA, is the most common subtype of anemia: half of all cases of anemia are IDA. IDA occurs when your body has low iron—usually due to bleeding or low iron in your diet—which your bone marrow needs to create hemoglobin, a protein in red blood cells responsible for transporting oxygen throughout the body.
Low hemoglobin will impact the blood’s ability to get oxygen to the inner ear. Without oxygen, those hair cells in the inner ear become damaged.
Sickle Cell Anemia
Sickle cell anemia is a hereditary subtype of anemia that causes abnormal, misshapen red blood cells. Red blood cells are typically round and flexible, but misshapen sickle cells are shaped like crescent moons, and they are rigid and sticky. Because of their abnormal shape, they can stick to blood vessels instead of travelling smoothly through them. They also break apart or die more quickly than normal red blood cells.
If sickle cells stick to the labyrinthine artery and block it, the artery will be impaired, which will affect the whole auditory system as that is the only artery that supplies blood to the inner ear.
Aplastic Anemia
This subtype of anemia occurs when the stem cells in bone marrow don’t make enough red blood cells, white blood cells or platelets. Platelets are cell fragments in the blood that clot together to stop bleeding when you’re injured. In very rare cases, profound hearing loss may occur spontaneously in individuals with aplastic anemia, and research suggests that bleeding in the cochlea, or a “cochlear hemorrhage,” is an underlying cause. Due to the low platelet count caused by aplastic anemia, the cochlear hemorrhage was not stopped, and hearing loss was permanent.
Anemia and Tinnitus
Anemia is also connected to tinnitus, which is a constant ringing or whooshing sound in the ear with no external source. Specifically, anemia can cause pulsatile tinnitus, in which the tinnitus sounds in the ear happen in time with your heartbeat (which is where the “pulse” part of “pulsatile” comes from). Often, pulsatile tinnitus is a symptom of diseases or disorders in your veins and arteries. It occurs when blood flow in the blood vessels near or around your ears is changed. As discussed, anemia can cause that to happen.
When To See a Doctor
Most of the research discussed here is still new, and there is much to explore regarding the link between anemia and hearing loss. The exact mechanism of anemia that can cause hearing loss or tinnitus is still unclear. However, if you are anemic, discuss treatment options with your healthcare provider. Treating anemia can treat or prevent hearing loss caused by anemia: one study showed that patients with hearing loss who received iron therapy showed better improvement than those who received other treatment options, and in more than half the patients, their hearing improved.
If you aren’t hearing like you used to, regardless of the cause, you should have a hearing test done by a hearing healthcare professional. They can determine your type of hearing loss and look for possible causes. Call Heuser Hearing Institute today to make an appointment.