High red blood cell (RBC) levels are not a common direct cause of heart palpitations, which are feelings that your heart is racing, pounding, fluttering, or skipping. However, palpitations and a high RBC count can occur together because of an underlying heart or lung condition, or another factor affecting your heartbeat. A high result should be interpreted with other blood tests and your symptoms.
Does a high RBC count directly cause heart palpitations?
A high RBC count means that a blood test has found more red blood cells than expected for the relevant reference range. These cells carry oxygen throughout the body. When their concentration becomes too high, the condition may be called erythrocytosis. In some cases, the increased concentration makes the blood thicker and raises the risk of blood clots.
Palpitations are not among the main symptoms usually associated with a high RBC count. More commonly reported symptoms include headaches, dizziness, tiredness, blurred vision, and shortness of breath. According to Cleveland Clinic, some people with a high RBC count have no noticeable symptoms, and further testing may be needed to identify the reason for the abnormal result.
Heart palpitations have several possible causes, including emotional stress, strenuous exercise, caffeine, certain medicines, thyroid problems, and abnormal heart rhythms. The Mayo Clinic explains that palpitations may occur for many reasons and are not always a sign of a serious heart problem.
Therefore, finding both a high RBC count and palpitations does not establish that one is causing the other. The underlying reason for the blood count abnormality, along with other possible causes of the heartbeat changes, needs to be considered.
What conditions can link a high RBC count and palpitations?
Several health conditions and everyday factors may help explain why these findings occur together. The connection depends on the cause of the elevated count and the circumstances in which the palpitations happen.
- Dehydration: Losing too much fluid can make the blood more concentrated and cause the RBC result to appear high. Dehydration may also occur alongside a faster heartbeat or a sensation of palpitations.
- Heart or lung conditions: Some heart and lung disorders reduce the amount of oxygen available to the body and can lead to an increased RBC count. These underlying conditions may also affect how the heart functions.
- Sleep apnea: Repeated interruptions in breathing during sleep can lower oxygen levels and contribute to a high RBC count. Sleep apnea may also be relevant when assessing certain heart rhythm problems.
- Smoking or living at high altitude: Both can contribute to an increased RBC count because of changes in oxygen exposure or availability.
- Polycythemia vera: This uncommon bone marrow disorder causes the body to produce too many red blood cells. It can make the blood thicker and increase the risk of blood clots.
According to MedlinePlus, other possible causes of a high RBC count include certain kidney conditions and the use of some performance-enhancing drugs. Identifying the underlying cause matters because management differs depending on whether the result reflects dehydration, reduced oxygen levels, or a disorder affecting blood cell production.
Can polycythemia vera cause heart-related symptoms?
Polycythemia vera is a specific blood disorder that causes the bone marrow to produce excessive blood cells, particularly red blood cells. The increased cell concentration can slow blood flow and raise the likelihood of clot formation. It is different from a temporary or apparent increase in RBC concentration caused by dehydration.
The Mayo Clinic's information on polycythemia vera identifies possible symptoms such as headaches, dizziness, tiredness, blurred vision, itching after a warm bath or shower, and shortness of breath. Palpitations alone do not establish that someone has this disorder.
If polycythemia vera is suspected, a healthcare professional may recommend additional blood tests and other investigations. The purpose is to determine whether the elevated RBC count represents a persistent blood disorder and whether treatment is needed to reduce the risk of complications.
How do doctors assess palpitations when the RBC count is high?
Evaluation usually considers the blood test results alongside the pattern of the palpitations, medical history, examination findings, and other symptoms. A single elevated RBC result does not necessarily mean that the body is producing too many red blood cells or that a serious condition is present.
Your healthcare professional may review the following information:
- Complete blood count (CBC): This shows the RBC count and other blood cell measurements.
- Hemoglobin and hematocrit: Hemoglobin measures the oxygen-carrying protein in red blood cells, while hematocrit measures the proportion of blood made up by those cells. These values help put the RBC count into context.
- Timing and pattern of palpitations: The clinician may ask whether the sensations begin during exercise, at rest, after caffeine, or alongside dizziness or breathlessness.
- Medical history and medicines: Smoking, fluid loss, sleep-related breathing problems, known heart or lung disease, and certain medicines may be relevant.
- Further tests when needed: Depending on the findings, testing may include an electrocardiogram (ECG), heart rhythm monitoring, oxygen measurement, or investigations into the cause of the high RBC count.
RBC reference ranges vary by laboratory and can differ according to age and sex. Children's results should be interpreted using appropriate age-specific ranges rather than adult values. Your clinician may also repeat the blood test if needed to determine whether the elevation persists.
What should you do if you have high RBC levels and palpitations?
If a blood test shows a high RBC count and you are experiencing palpitations, arrange a medical assessment, especially if the sensations are recurring, worsening, prolonged, or interfering with daily activities. Bring your blood test report and a list of medicines and supplements you use. Recording when the palpitations occur, how long they last, and any associated symptoms can help your clinician assess the pattern.
If dehydration may be contributing and you can drink fluids safely, replacing fluids may be appropriate. However, do not assume dehydration explains a persistently elevated result. Avoid trying to lower your RBC count through blood donation, aspirin, or other treatments unless a healthcare professional recommends this for your circumstances.
If a specific underlying cause is identified, treatment will focus on that cause and any associated risks. For example, persistent elevation related to low oxygen levels requires a different approach from a bone marrow disorder. A high RBC count alone does not determine which treatment, if any, is appropriate.
When should you seek urgent medical care?
Seek emergency medical attention if palpitations occur with chest pain or discomfort, fainting, or severe shortness of breath. Severe dizziness accompanying palpitations also warrants urgent assessment.
A high RBC concentration can increase the risk of blood clots in some conditions. Sudden breathlessness, chest or upper back pain, coughing up blood, or new pain and swelling in one leg may indicate a clot and require immediate medical evaluation. Do not wait for a routine appointment if these symptoms develop.
If palpitations are new or repeatedly return, even without emergency warning signs, arrange a medical review. Identifying the reason for both the heartbeat symptoms and the abnormal blood result can help determine whether further investigation or treatment is necessary.