How do you treat high hematocrit? Understanding and Managing Elevated Blood Counts

October 1, 2025 •

4 min read

According to the Cleveland Clinic, dehydration is the most common cause of a high hematocrit, where a decrease in plasma volume leads to a higher concentration of red blood cells. Therefore, the path to understanding and addressing the question, 'How do you treat high hematocrit?' often begins with a thorough medical evaluation to identify the root cause.

Quick Summary

Treatment for high hematocrit depends on the cause and may involve therapeutic phlebotomy, medications to reduce red blood cell production, and low-dose aspirin to prevent clots. Lifestyle changes, including hydration, quitting smoking, and addressing underlying conditions like sleep apnea or TRT use, are also crucial for management.

Key Points

Identify the Root Cause: High hematocrit is a symptom, and treatment must address the underlying cause, whether dehydration, illness, or a blood disorder.
Phlebotomy is a Core Treatment: Therapeutic phlebotomy (blood removal) is a primary method to quickly lower red blood cell count for conditions like polycythemia vera.
Medications Suppress Production: Drugs like hydroxyurea and interferon-alpha help slow red blood cell production, especially in chronic disorders.
Low-Dose Aspirin Prevents Clots: Low-dose aspirin is often prescribed to prevent dangerous blood clots associated with thicker blood.
Lifestyle Modifications are Crucial: Staying hydrated, quitting smoking, and moderate exercise are fundamental for managing high hematocrit.
Address Other Health Issues: Resolving issues like sleep apnea or adjusting testosterone replacement therapy (TRT) can help normalize hematocrit levels.

Understanding the Need to Treat High Hematocrit

High hematocrit, also known as erythrocytosis, indicates an elevated volume of red blood cells (RBCs) in the blood. This condition can make the blood thicker and more viscous, increasing the risk of serious complications such as blood clots, stroke, and heart attack. The appropriate course of action for managing high hematocrit is not one-size-fits-all, as it is entirely dependent on the underlying cause, which can range from a benign and temporary issue like dehydration to a chronic, progressive blood disorder like polycythemia vera (PV). A healthcare provider's diagnosis is the first and most critical step before initiating any treatment.

Medical Treatments for High Hematocrit

Depending on the specific diagnosis, a doctor may recommend one or more medical interventions to bring hematocrit levels back into a safe range and mitigate risks.

Phlebotomy: A Primary Procedure

Therapeutic phlebotomy is a standard treatment for many causes of elevated hematocrit, especially polycythemia vera. This procedure removes a unit of blood to decrease the volume of red blood cells, aiming to maintain hematocrit below 45%. The frequency varies based on the individual's condition.

A needle is inserted into a vein.
Blood is collected.
The procedure is repeated as needed.

Medications to Control Red Blood Cell Production

Medications may be prescribed to suppress bone marrow overproduction of red blood cells, particularly for polycythemia vera or severe symptoms.

Hydroxyurea: Reduces red blood cells and platelets and is often used for high-risk PV patients.
Interferon-alpha: Helps regulate bone marrow cell activity. Peginterferon alfa is a longer-acting option.
Ruxolitinib: A targeted therapy for patients not responding to or tolerating hydroxyurea.

Low-Dose Aspirin for Prevention

Low-dose aspirin (e.g., 81 mg daily) is frequently recommended for conditions like polycythemia vera to prevent blood clots, which are a risk with high hematocrit. Aspirin inhibits platelet aggregation and can also help with related symptoms. Discuss this option with your doctor, especially if you have bleeding issues.

Addressing Underlying Causes

Effectively treating high hematocrit requires addressing the root cause, especially in secondary erythrocytosis, as simply treating the symptom is not a long-term solution.

Treating Dehydration

Dehydration, the most common cause of temporary high hematocrit, is treated by restoring fluid balance. Mild cases can be managed with oral rehydration, while severe cases may require intravenous fluids.

Managing Sleep Apnea

Sleep apnea causes low oxygen levels, leading to increased red blood cell production. Treating sleep apnea with CPAP can normalize oxygen and reduce hematocrit.

Adjusting Testosterone Replacement Therapy (TRT)

TRT can cause high hematocrit. Management under medical supervision may involve reducing the dose, switching to a different formulation (like gels), or using therapeutic phlebotomy.

Managing Chronic Heart or Lung Disease

Chronic low oxygen due to heart or lung conditions can cause high hematocrit. Treating the underlying disease and using supplemental oxygen can help.

Lifestyle Changes for Long-Term Management

Lifestyle adjustments are crucial for managing high hematocrit and preventing complications.

Stay hydrated: Drink plenty of water and avoid excessive alcohol or caffeine.
Quit smoking: Smoking causes low oxygen and stimulates red blood cell production; quitting can improve levels.
Exercise moderately: Regular exercise improves circulation and reduces clot risk.
Avoid high altitudes: Moving to a lower altitude may help normalize levels for some individuals.
Adjust diet: Avoid unnecessary iron supplements and discuss dietary changes with your doctor.

Comparison of Treatment Approaches


Feature	Primary Polycythemia Vera (PV)	Secondary Erythrocytosis	Temporary High Hematocrit (e.g., Dehydration)
Underlying Cause	A bone marrow disorder where the body produces too many RBCs.	Caused by an external factor like low oxygen, TRT, or disease.	Caused by reduced blood plasma volume, usually from fluid loss.
Primary Treatment	Therapeutic phlebotomy to remove excess blood.	Addressing and treating the root cause (e.g., sleep apnea, TRT).	Rehydration with oral or intravenous fluids.
Medications	Myelosuppressive drugs (hydroxyurea, interferon) to control RBC production. Low-dose aspirin for clot prevention.	Focused on managing the underlying condition. Low-dose aspirin may be considered.	Typically no medication needed, unless for underlying issues.
Lifestyle Changes	Crucial for long-term management alongside medical care.	Focused on addressing the specific cause (e.g., quitting smoking).	Rehydration and avoiding diuretics like excessive alcohol.
Monitoring	Regular phlebotomy and blood count monitoring are essential.	Monitoring to ensure the underlying condition is controlled.	Re-checking hematocrit after adequate hydration.

Conclusion

Treating high hematocrit requires identifying the specific cause. For chronic conditions like polycythemia vera, treatments include therapeutic phlebotomy and medications to control red blood cell count and reduce clotting risks. For secondary causes such as sleep apnea or testosterone therapy, addressing the primary issue is key. Simple lifestyle changes like hydration and quitting smoking are also vital. All treatment decisions should be made with a healthcare professional who can perform necessary tests and create a personalized plan. The Mayo Clinic offers additional guidance on polycythemia vera management.

Frequently Asked Questions

The fastest way to lower hematocrit, particularly when levels are very high, is through therapeutic phlebotomy, a procedure that removes excess blood.

Yes, if high hematocrit is due to dehydration, drinking more water increases plasma volume, diluting red blood cells and lowering the percentage.

Avoid unnecessary iron supplements as iron aids red blood cell production. Discuss all supplements with your doctor.

Yes, quitting smoking is crucial. Smoking causes low oxygen, stimulating red blood cell production. Quitting helps normalize oxygen and reduce production.

Yes, TRT, especially injections, can stimulate red blood cell production. Management may involve dose adjustment, changing formulation, or phlebotomy.

While medical treatment is often needed, natural strategies include hydration, moderate exercise, and quitting smoking. Discuss any other methods with a doctor.

No. While it can be linked to conditions like polycythemia vera, it's often caused by benign issues like dehydration or high altitudes. A doctor's evaluation is needed.