Secondary Polycythemia (Erythrocytosis)
What is Secondary polycythemia (erythrocytosis)?
Secondary polycythemia is a condition where your body produces too many red blood cells in response to low oxygen levels. The extra red blood cells thicken your blood and make it harder to flow through your veins and arteries. This happens when your body tries to compensate for not getting enough oxygen.
Unlike primary polycythemia, which is caused by a bone marrow disorder, secondary polycythemia develops because something in your environment or body is triggering extra red blood cell production. Your kidneys sense low oxygen and release a hormone called erythropoietin, which tells your bone marrow to make more red blood cells. While this response is meant to help, too many red blood cells can lead to serious health problems.
Secondary polycythemia can develop slowly over time or appear more quickly depending on the cause. Many people discover they have this condition through routine blood work before they notice any symptoms. Early detection through blood testing helps you address the root cause and prevent complications like blood clots or stroke.
Symptoms
Many people with secondary polycythemia have no symptoms early on, especially if the condition develops gradually. When symptoms do appear, they often include:
- Headaches that feel dull or throbbing
- Dizziness or lightheadedness
- Blurred or double vision
- Ringing in the ears, called tinnitus
- Fatigue and weakness despite resting
- Shortness of breath during normal activities
- Redness in the face, hands, or feet
- Itching, especially after a warm bath or shower
- Numbness or tingling in hands and feet
- Chest pain or discomfort
Some people feel generally unwell but cannot pinpoint specific symptoms. Because secondary polycythemia develops in response to another condition, you may also notice symptoms related to the underlying cause, such as breathing problems from lung disease or sleep disruption from sleep apnea.
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Causes and risk factors
Secondary polycythemia occurs when your body responds to chronic low oxygen levels by producing extra red blood cells. Common causes include living at high altitudes where oxygen is thinner, chronic lung diseases like COPD or pulmonary fibrosis, and obstructive sleep apnea that disrupts breathing during sleep. Heavy smoking damages lung function and reduces oxygen delivery to tissues, triggering increased red blood cell production. Heart defects present from birth can also cause poor oxygenation and lead to this condition.
Some kidney tumors or cysts produce excess erythropoietin hormone, signaling the bone marrow to make more red blood cells even when oxygen levels are normal. Certain other tumors, including liver cancer and uterine fibroids, can have the same effect. Testosterone therapy and performance-enhancing drugs used by some athletes artificially stimulate red blood cell production. Risk factors include smoking tobacco, living at elevations above 8,000 feet, having untreated sleep apnea, chronic lung or heart disease, and family history of blood disorders.
How it's diagnosed
Secondary polycythemia is diagnosed primarily through blood testing that measures your red blood cell count and related values. An elevated RBC count is the key finding that indicates you may have this condition. Your doctor will also check your hemoglobin and hematocrit levels, which measure how much oxygen-carrying protein is in your blood and what percentage of your blood is made up of red blood cells. Rite Aid offers testing that includes RBC count measurement to help detect elevated red blood cell levels early.
After finding elevated red blood cells, your doctor will work to identify the underlying cause. This may include measuring oxygen saturation levels, testing erythropoietin hormone levels, and evaluating lung and heart function. Imaging studies like chest X-rays or sleep studies may be ordered to check for lung disease or sleep apnea. Identifying the root cause is essential because treatment focuses on addressing what triggered your body to produce extra red blood cells in the first place.
Treatment options
Treatment for secondary polycythemia focuses on addressing the underlying condition causing low oxygen or excess erythropoietin production. Lifestyle changes and medical treatments may include:
- Quitting smoking to improve lung function and oxygen delivery
- Using CPAP therapy if you have sleep apnea to maintain oxygen levels during sleep
- Treating lung diseases with medications and breathing therapies
- Moving to lower altitudes if high elevation is the cause
- Staying well hydrated to help thin your blood
- Avoiding activities that could lead to blood clots
- Phlebotomy, which means removing blood periodically to reduce red blood cell levels
- Low-dose aspirin to reduce clot risk in some cases
- Treating underlying tumors or kidney problems producing excess erythropoietin
- Adjusting or stopping testosterone or performance-enhancing drugs
Your doctor will create a treatment plan based on what is causing your elevated red blood cell count. Regular monitoring through blood tests helps track whether treatment is working. If you have symptoms like severe headaches, chest pain, vision changes, or difficulty breathing, seek medical attention right away as these may indicate complications.
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- Simple blood draw at your nearest lab
- Results in days, not weeks
- Share results with your doctor
Frequently asked questions
Primary polycythemia is caused by a bone marrow disorder where your body makes too many red blood cells without a clear reason. Secondary polycythemia happens when your body produces extra red blood cells in response to low oxygen levels or other triggers like lung disease, high altitude, or smoking. The treatments differ because secondary polycythemia requires addressing the underlying cause, while primary polycythemia focuses on managing the bone marrow disorder itself.
Secondary polycythemia can resolve if the underlying cause is successfully treated or removed. For example, if you quit smoking or move to a lower altitude, your red blood cell count may gradually return to normal. However, if the cause is a chronic condition like lung disease or sleep apnea, ongoing treatment is usually needed to manage red blood cell levels. Regular blood testing helps monitor your progress and shows whether treatment is working.
Testing frequency depends on the severity of your condition and how well your treatment is working. Most people need blood tests every 3 to 6 months to monitor red blood cell counts and ensure levels stay in a safe range. If you are starting new treatment or your counts are very high, your doctor may want to test you more frequently, such as monthly. Rite Aid offers convenient blood testing at Quest Diagnostics locations to help you stay on top of your monitoring.
Yes, if left untreated, secondary polycythemia can lead to serious complications. Thick blood from too many red blood cells increases your risk of blood clots, which can cause stroke, heart attack, or deep vein thrombosis. You may also develop bleeding problems because thick blood does not flow properly through small vessels. Early detection through blood testing and proper treatment of the underlying cause significantly reduce these risks.
While no specific diet treats secondary polycythemia, staying well hydrated is important to help keep your blood from becoming too thick. Some doctors recommend avoiding iron supplements unless you are truly iron deficient, as extra iron can stimulate more red blood cell production. Limit alcohol intake, which can worsen dehydration. Focus on a balanced diet rich in vegetables, fruits, and whole grains to support overall health while you address the underlying cause.
Yes, living at high altitudes above 8,000 feet is a common cause of secondary polycythemia. At higher elevations, the air contains less oxygen, so your body compensates by producing more red blood cells to carry the oxygen you need. This is a normal adaptation, but it can become problematic if red blood cell counts get too high. Moving to a lower altitude often resolves the condition over time as your body adjusts to normal oxygen levels.
Phlebotomy is a procedure where a healthcare provider removes a specific amount of blood from your body, similar to donating blood. This reduces the number of red blood cells circulating in your system and helps thin your blood. For secondary polycythemia, phlebotomy is used as a temporary measure while you address the underlying cause. Some people need phlebotomy every few weeks until their red blood cell count stabilizes, while others may need it less frequently or not at all once the root cause is treated.
Yes, untreated obstructive sleep apnea is a significant cause of secondary polycythemia. When your breathing stops repeatedly during sleep, your blood oxygen levels drop. Your body senses this lack of oxygen and responds by making more red blood cells to improve oxygen delivery. Using CPAP therapy to keep your airway open during sleep can restore normal oxygen levels and often brings red blood cell counts back to normal over several months.
Low-dose aspirin is sometimes recommended for people with secondary polycythemia to reduce the risk of blood clots. However, you should only take aspirin if your doctor specifically prescribes it, as it can increase bleeding risk in some situations. Your doctor will consider your overall health, clot risk, and red blood cell levels before recommending aspirin. Never start aspirin therapy on your own without medical guidance.
The duration of treatment depends entirely on what is causing your secondary polycythemia. If the cause can be eliminated, such as quitting smoking or treating a tumor, you may not need ongoing treatment once your red blood cell count returns to normal. However, if you have a chronic condition like COPD or live at high altitude permanently, you may need long-term monitoring and treatment. Regular blood tests help your doctor determine whether continued treatment is necessary.