Paroxysmal nocturnal hemoglobinuria (PNH) causes a variety of symptoms that can be different for each person. PNH can also worsen at different speeds. For example, one person may have only a couple of mild symptoms that stay the same for years, while someone else may develop many symptoms that eventually turn into serious health problems.

Thanks! You've successfully submitted your vote.

Sign up to view the results!

Continue with Facebook

Continue with Google

Continue with your email

By joining, you accept our Terms of Use, and acknowledge our collection, sharing, and use of your data in accordance with our Health Data and Privacy policies.

Already a Member? Log in

If you have PNH, you may have one or many of the symptoms listed below. It’s possible to have PNH and never experience all these symptoms. Your symptoms may also change over time.

PNH often leads to hemolytic episodes, in which red blood cells are destroyed and PNH symptoms become worse. Hemolytic episodes are more likely to happen in response to physical or mental stress, including an infection, surgery, pregnancy, vaccination, or a condition that causes inflammation.

Your PNH symptoms may change over time.

Talk to your doctor if you have any of the signs from the paroxysmal nocturnal hemoglobinuria symptom checklist below.

1. Red or Brown Urine

The name “paroxysmal nocturnal hemoglobinuria” comes from a symptom called hemoglobinuria, which means reddish or brownish urine. This symptom may occur at any time but is often more noticeable in the morning. Hemoglobinuria is caused by a high amount of hemoglobin — a pigment in red blood cells — leaking into the urine.

2. Fatigue

PNH can lead to anemia (low levels of red blood cells), which can cause fatigue — ​persistent tiredness or weakness that doesn’t improve with rest. In PNH, the immune system attacks red blood cells and breaks them apart. When red blood cell levels drop, this is known as hemolytic anemia.

Additionally, PNH may coexist with bone marrow failure or bone marrow disorders. This happens when the hematopoietic stem cells in the spongy tissue inside bones stop working correctly. These cells make new red blood cells, but in people with PNH, they don’t make enough healthy ones.

In addition to causing fatigue, low red blood cell counts can lead to:

• Feelings of dizziness or confusion
• Dyspnea (shortness of breath)
• Headache
• A fast or irregular heartbeat
• Chest pain
• Decreased appetite
• Unexpected weight loss
• Pale skin
• Jaundice (a yellow tint to your skin or the whites of your eyes)
• Difficulty with focusing
• Feelings of irritation

These symptoms of anemia may come and go based on how well your PNH is being controlled with treatments.

3. Pain

Anemia can cause certain types of pain. You might get a headache if your red blood cells aren’t carrying enough oxygen to your brain. Low oxygen levels can also make your heart work harder, which may lead to chest pain or pressure.

4. Muscle Spasms

Extra hemoglobin in blood can attach to and block nitric oxide, a chemical that muscles need to stay relaxed. If PNH leads to low nitric oxide levels, you may experience cramping or muscle spasms, which could lead to symptoms like muscle or abdominal pain.

Spasms in your esophagus (the tube that carries food from the mouth to the stomach) may cause swallowing problems. Muscle spasms can also lead to erectile dysfunction — the inability to have or maintain an erection.

At leaset a third of people with PNH develop blood clots.

5. Blood Clots

Platelets are small cell fragments in blood. A blood clot develops when platelets clump together and prevent a blood vessel from leaking too much blood after an injury. However, when an abnormal blood clot forms in a vein, it can cause life-threatening health problems.

At least one-third of people with PNH develop blood clots. Possible reasons include low nitric oxide levels or abnormal platelets.

Blood clots can cause different symptoms depending on where they form in the body. Here are common symptoms based on the location of the clot:

• Brain (stroke) — Severe headache, numbness, weakness on one side of the body, trouble speaking, or vision problems
• Abdomen — Belly pain, swelling, bloating, or a feeling of warmth
• Liver — Belly pain or jaundice
• Leg or arm (deep vein thrombosis) — Swelling, warmth, or pain in one limb
• Lung (pulmonary embolism) — Chest pain, shortness of breath, dizziness, anxiety, sweating, irregular heartbeat, or coughing up blood
• Skin — Discoloration, warmth, swelling, or pain

Blood clots can be serious if they’re not treated right away. Get emergency medical care if you have PNH and think you may have a blood clot.

6. Abnormal Bleeding and Bruising

Although some people with PNH form blood clots too easily, others may have the opposite problem. Thrombocytopenia (low platelet levels) can lead to symptoms related to poor blood clotting. These include:

• Frequent bruising
• Bleeding more than usual from a small injury
• Repeated nosebleeds
• Bloody gums
• Petechiae (tiny spots on the skin)
• Heavy menstrual periods

If you experience ongoing bleeding that won’t stop, get emergency medical care.

You may develop infections more often than usual if you have PNH.

7. Infections

Because PNH is partly caused by problems with the stem cells that produce all the other types of blood cells, some people with this rare disease have low white blood cell levels. These cells are responsible for fighting off germs, so you may develop infections more often than usual if you have PNH.

Neutropenia (low white blood cell counts) may cause frequent fevers, sinus infections, lung infections, skin infections, bladder infections, or mouth sores.

8. Kidney Problems

Rarely, PNH causes kidney problems. It’s possible that the breakdown of red blood cells causes a buildup of iron in the kidneys or that blood clots may form in the kidneys’ veins. In some cases, the cause of kidney problems isn’t understood.

Symptoms of kidney damage include ankle swelling, inflammation around the eyes, shortness of breath, nausea, confusion, and less frequent urination.

9. Inflammation

In very rare cases, PNH is accompanied by inflammation that causes additional symptoms, including:

• Hives (an itchy, raised rash)
• Joint or bone pain
• Inflammatory bowel disease (IBD), which often leads to digestive symptoms like abdominal pain, diarrhea, blood in the stool, fatigue, and weight loss
• Meningitis (swelling of the tissue around the brain and spinal cord), which may cause a stiff neck, headache, nausea, seizures, or confusion

Getting Help for Symptoms of PNH

PNH frequently occurs with related conditions such as aplastic anemia and myelodysplastic syndrome. Some of your symptoms could be connected to one of these conditions.

Experiencing potential PNH symptoms doesn’t necessarily mean you have this condition. However, if you’re having issues like dark urine, fatigue, muscle spasms, blood clots, or bleeding problems, you should talk with your healthcare provider. Your doctor or a specialist, such as a hematologist-oncologist, can run tests to see if you have a problem with your blood cells and investigate the cause.

If you receive a diagnosis of PNH, your doctor can recommend various therapies. PNH treatment options may eliminate or reduce your symptoms and boost your quality of life and sense of well-being.

Join the Conversation

On myPNHteam, people share their experiences with paroxysmal nocturnal hemoglobinuria, get advice, and find support from others who understand.

Which PNH symptoms have you experienced? Let others know in the comments below.