Are you feeling unusually tired or getting frequent headaches? Let us explore what happens when your body makes too many red blood cells.

Have you ever felt tired for no clear reason, had a stubborn headache, or felt weak all over? We often brush off these small signs and go about our day. Yet, deep inside your body, your red blood cell count might be higher than normal.

When this happens, doctors call it erythrocytosis or sometimes polycythemia. This medical condition deserves your attention and care.

Today, we will explore what erythrocytosis is, why it happens, how doctors find it, and what you can do to stay healthy.

What Is Erythrocytosis?

Simply put, erythrocytosis means that the concentration of red blood cells (erythrocytes) in your blood is higher than normal. Your blood has two main parts. One part is solid, made of red blood cells, white blood cells, and platelets. The other part is liquid, known as plasma. In erythrocytosis, your red blood cells increase compared to the liquid plasma.

If you take a blood test, your report will show two vital numbers called hematocrit (HCT) and hemoglobin (HB).

• Hematocrit (HCT): This tells you the percentage of your blood volume made up of red blood cells.
• Hemoglobin (HB): This is the important protein inside red blood cells that carries oxygen all over your body.

During erythrocytosis, either your hematocrit value, your hemoglobin value, or both will be higher than the standard range.

How Excess Red Blood Cells Affect Your Body.

Red blood cells are essential for your health. They carry oxygen from your lungs to every single cell and tissue in your body. This keeps your tissues nourished and healthy.

However, having too many red blood cells can cause problems. It depends on why your red blood cells increased in the first place. Some effects are mild, such as simple headaches and fatigue. But other serious causes can make your blood thick and sluggish. Thick blood raises your risk of dangerous health issues like blood clots, heart attacks, or strokes.

This is why finding the exact cause with your doctor is so important. Proper care helps relieve your symptoms and protects you from severe complications.

Main Types of Erythrocytosis.

Doctors divide erythrocytosis into two main types based on how the red blood cells increase:

1. Absolute Erythrocytosis: Your body actually produces a higher number of red blood cells than normal.

2. Relative Erythrocytosis: Your total red blood cell count may be normal. However, the liquid plasma in your blood drops, making your red blood cell concentration look higher. For example, if you lose body water from severe vomiting or diarrhea, your blood volume drops and creates this temporary spike.

Absolute erythrocytosis splits further into two categories based on the root cause:

Primary Erythrocytosis.

In primary erythrocytosis, the issue starts in your bone marrow. Your bone marrow is the factory inside your bones that builds blood cells. In this condition, a genetic defect in your bone marrow stem cells causes your body to make red blood cells without normal limits. You can inherit this genetic change from your parents or acquire it later in life.

• Acquired Primary Erythrocytosis: A prime example is Polycythemia Vera. Many people confuse erythrocytosis and polycythemia vera as the exact same thing, but they are not. Polycythemia vera is one specific and serious disease that causes erythrocytosis.
• Inherited Primary Erythrocytosis: Sometimes, gene changes passed down through families instruct bone marrow to build too many red blood cells.

Secondary Erythrocytosis.

In secondary erythrocytosis, the problem does not start in your bone marrow. Instead, an outside factor drives the increase. Most often, secondary erythrocytosis happens when your body produces too much erythropoietin (EPO) hormone. EPO acts like a chemical messenger that tells your bone marrow to make more red blood cells.

Imagine you have a lung disease or a heart condition. Your body gets less oxygen. To fix this, your body makes more EPO hormone to stimulate your bone marrow to produce more red blood cells so it can carry more oxygen. But when this process goes too far, it leads to secondary erythrocytosis. Certain genetic conditions outside the bone marrow can also cause this.

Blood Test Values for Erythrocytosis.

What counts as a normal red blood cell level varies from person to person. Your age, sex, and the altitude of where you live all influence these numbers.

Doctors usually diagnose erythrocytosis when your hematocrit (HCT) and hemoglobin (HB) numbers rise above standard limits. These numbers are measured using a routine Complete Blood Count (CBC) test.

For Adult Males:

• Hematocrit (HCT): Above 50% .
• Hemoglobin (HB): Above 17.5 g/dL .

For Non-Pregnant Adult Females:

• Hematocrit (HCT): Above 45% .
• Hemoglobin (HB): Above 15.3 g/dL .

Important Note: These numbers serve as a general guide. Your doctor will decide if you have erythrocytosis by looking at your entire medical history and overall health.

Causes of Relative Erythrocytosis.

Relative erythrocytosis happens when your body water drops, reducing your blood plasma and making your red blood cells more concentrated. The most common cause is dehydration.

• Severe vomiting that will not stop .
• Ongoing diarrhea .
• Certain medicines, such as diuretics (water pills) prescribed for high blood pressure or fluid retention.

These factors lower your body fluid levels and trigger relative erythrocytosis.

Causes of Absolute Erythrocytosis.

Absolute erythrocytosis has distinct causes for its primary and secondary types.

Causes of Primary Erythrocytosis.

Primary cases usually stem from genetic changes that directly affect the bone marrow.

• Polycythemia Vera and other myeloproliferative neoplasms: These are rare bone marrow disorders where your body overproduces red blood cells and other blood cells. Polycythemia vera is the most common condition in this group.
• Inherited genetic mutations: Some people are born with gene variations that tell their bone marrow to make excess red blood cells.

Causes of Secondary Erythrocytosis.

Secondary cases usually result from high EPO hormone levels or low oxygen states.

• Low tissue oxygen levels:
  • Lung diseases like chronic bronchitis or emphysema .
  • Heart diseases such as congenital heart defects .
  • Sleep apnea .
  • Hemoglobinopathy disorders where your red blood cells cannot release oxygen properly .
• Kidney conditions and transplants:
  • Narrowing of the arteries that supply blood to your kidneys (Renal Artery Stenosis) .
  • Swelling and fluid buildup in the kidneys (Hydronephrosis) .
  • Sometimes occurs after a kidney transplant .
• Tumors: Certain cancerous and non-cancerous growths secrete excess EPO hormone.
  • Cancerous tumors: Renal cell carcinoma, hemangioblastoma, hepatocellular carcinoma, and parathyroid carcinoma .
  • Non-cancerous growths: Uterine fibroids, pheochromocytoma, and meningioma .
• Carbon monoxide poisoning and smoking: Heavy smoking causes carbon monoxide buildup in your blood, lowering tissue oxygen levels and driving up red blood cell counts.
• Certain drugs and substances:
  • Anabolic steroids used for muscle growth .
  • Testosterone hormone therapy .

Symptoms of Erythrocytosis.

Your symptoms and their severity depend entirely on the underlying cause of your erythrocytosis. For example, people with secondary erythrocytosis often experience:

• Headaches .
• Feeling confused or having trouble focusing .
• Trouble sleeping well .
• Low energy and constant fatigue .

People with primary erythrocytosis, especially conditions like polycythemia vera, may notice more intense symptoms:

• High blood pressure .
• Heavy sweating, especially at night .
• Unexplained weight loss .
• Severe joint pain, swelling, and redness, known as gout.
• Easy bleeding or bruising, such as frequent nosebleeds .
• Itchy skin, which often gets worse after taking a warm bath or shower .
• Numbness or a tingling sensation in your hands and feet .
• A reddish, flushed appearance in your face, hands, and feet .

How Doctors Diagnose Erythrocytosis.

Your doctor will start by finding out why your red blood cell count is high. They use several tests and methods to reach an accurate diagnosis.

First, they will review your medical history, current medicines, lifestyle habits like smoking, and your symptoms. They will check if you have relative erythrocytosis due to dehydration and perform a physical exam.

Next, they will determine if your condition is primary or secondary using targeted diagnostic tests.

What Tests Are Done?

• Complete Blood Count (CBC): Measures your red blood cell count, hemoglobin (HB), and hematocrit (HCT) levels.
• Peripheral Blood Smear (PBS): Examines a drop of blood under a microscope to check if your blood cells look normal in shape and size. Conditions like polycythemia vera show distinct cellular changes.
• Kidney and Liver Function Tests: Check for underlying kidney disease or tumors that might produce excess EPO.
• Pulse Oximetry: Uses a small sensor on your finger to measure your blood oxygen level, helping rule out lung or heart issues.
• Erythropoietin (EPO) Level Test: Low EPO levels point toward primary erythrocytosis, while high EPO levels suggest secondary erythrocytosis.
• Urinalysis: Checks your urine for abnormalities or red blood cells that indicate kidney problems.

If your doctor suspects polycythemia vera, they may recommend a bone marrow biopsy for further confirmation.

Treatments for Erythrocytosis.

Many underlying causes of erythrocytosis cannot be completely cured. However, modern treatments manage your symptoms and lower your risk of complications like dangerous blood clots.

Your doctor will choose the right treatment plan for your specific diagnosis. They will also treat any underlying medical conditions causing your high red blood cell count.

What to Expect if You Have This Condition.

Your outlook depends entirely on the cause of your erythrocytosis and how severe it is. For example, some inherited primary forms cause mild symptoms that pose no threat to your life. However, serious conditions like polycythemia vera require lifelong medical monitoring and treatment.

How to Take Care of Yourself.

The most important step is to follow your doctor's instructions closely. In addition to medical treatment, these lifestyle habits support your health:

• Quit smoking right away if you currently smoke.
• Maintain a healthy body weight through balanced nutrition.
• Control high blood pressure with proper diet and care.
• Avoid high-altitude mountain regions if your doctor advises you to stay at sea level.