What Complications Happen With Polycythemia Vera?

Medically Reviewed by Jennifer Robinson, MD on November 16, 2022
4 min read

Many people with polycythemia vera (PV) live a normal life with this rare blood cancer under control. The goal is to avoid complications like blood clots, which may happen because PV thickens your blood.

To prevent those problems, your doctor will recommend treatments to improve your blood flow and help you feel better. 

When blood gets thick, it can stick together and form clots inside your veins. This can happen in different places in your body.

Deep vein thrombosis (DVT) is a clot in a vein deep inside your leg.

Sometimes a clot gets loose and travels through a blood vessel. From there, it can move into your lung and get stuck. This is a pulmonary embolism, and it’s an emergency. 

A clot can also lodge in the brain and cause a stroke. Or it can block a blood vessel in the heart and cause a heart attack.

These problems don’t happen to everyone who has polycythemia vera. They’re more likely if you’re older than 60 or have already had a blood clot or complication. You’ll want to work with your doctor to get a sense of your risk and how to lower it.

Watch for signs of a clot, such as:

  • Chest pain
  • Shortness of breath
  • Dizziness
  • Pain and swelling in your leg

Call your doctor or go to an emergency room right away if you have these signs. It could be something else, but you need to find out ASAP.

A blood clot can also form in the main blood vessel that leads to the liver. This rare condition is called Budd-Chiari syndrome. Its symptoms may include:

  • Pain in the upper right part of your belly
  • Yellow color in your skin and the whites of your eyes
  • Swelling in the belly or arms
  • Bleeding in your digestive tract, from the esophagus or gut

To prevent clots, your doctor will remove a small amount of blood with a treatment called phlebotomy. This is similar to giving blood during a blood drive. You may also get medicines like low-dose aspirin, hydroxyurea, or interferon alfa to thin your blood and stop your body from making too many blood cells.

Blood carries oxygen around your body. When PV slows blood flow, it's hard for oxygen to reach your organs.

Signs that your body isn't getting enough oxygen include:

  • Fatigue
  • Weakness
  • Headache
  • Dizziness
  • Shortness of breath
  • Ringing in your ears
  • Vision changes, such as flashes of light
  • Chest pain

PV treatments can improve blood flow and oxygen transport to prevent these symptoms.

Sometimes polycythemia vera prompts your body to make extra platelets. Platelets normally help your blood clot, but the extra ones in PV don't always work well. They prevent your blood from clotting the way it should.

Some people with this condition bleed too easily. They may have:

  • Bleeding gums
  • A bleeding ulcer or other bleeding in the GI tract
  • Nosebleeds
  • Bruises or pooled blood under the skin

If you take aspirin to prevent clots, it could make the bleeding worse. Your doctor might need to change your medicine until the bleeding is under control.

Some people with PV -- about 4 out of 10 -- have itchy skin.

Many things can cause itching. With PV, it can happen because the extra red blood cells prompt your immune system to release a chemical called histamine. This is the same chemical your body releases during an allergic reaction. Histamine makes your skin itch.

To prevent itchiness:

  • Keep the water cool when you shower or take a bath.
  • Gently pat your skin dry when you get out of the water. Don’t rub it dry.
  • Use moisturizer every day.

Your doctor may recommend an antihistamine or low-dose aspirin.

A rise in histamine levels also causes your stomach to make more acid. This acid can leave sores called peptic ulcers in the lining of your esophagus, stomach, or small intestine. When you have PV, these are about 3 to 5 times more likely than in other people.

If you get an ulcer, you'll likely have stomach pain, along with nausea, vomiting, and a feeling of fullness. You may also feel fatigued and have dark, tarry stools. Doctors treat ulcers and prevent new ones from forming with medicines that curb acid production, such as proton pump inhibitors or H2 blockers.

Your spleen is in the upper left part of your belly. One of its main jobs is to recycle old red blood cells.

PV makes the spleen work harder to remove all the extra blood cells. All that extra work makes the spleen grow bigger. About 3 out of 4 people with PV have an enlarged spleen. Doctors call this “splenomegaly.”

If your spleen is enlarged, you may have symptoms like:

  • A feeling of fullness
  • Swelling in your belly
  • Weight loss
  • Stomach pain

If your enlarged spleen causes problems, you may need to take medicine for it, or you may need surgery to remove it.

Gout is a type of arthritis. It's caused by the buildup of uric acid in your joints.

Uric acid forms into hard crystals that leave the joints sore and swollen. You get gout when cells turn over too quickly in your body -- like in PV.

Signs of gout include swelling and pain in your joints, especially in your big toe. Your doctor can prescribe medicines such as allopurinol to control gout and prevent future attacks. 

After years of pumping out extra red blood cells, your bone marrow can become so filled with scar tissue that it can't make enough blood cells to meet your body's needs. Doctors call this condition myelofibrosis.

It’s rare, but abnormal bone marrow cells grow out of control. This can lead to acute myelogenous leukemia, a cancer of the blood and bone marrow.

Again, these problems aren’t likely. Your doctor will closely follow your health to make sure you’re doing well and staying free of complications.