Paroxysmal nocturnal hemoglobinuria (PNH) causes a wide range of symptoms that vary for different people. PNH can also worsen at different rates. For example, one person may have just a couple of mild symptoms that stay the same for several years, while another may have many symptoms that eventually turn into serious health problems.

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 of 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 worsen. This is more likely to happen when you undergo periods of physical or mental stress, including experiencing an infection, surgery, pregnancy, vaccination, or a condition that causes inflammation.

Talk to your doctor if you experience any of the following signs and symptoms of PNH.

1. Red or Brown Urine

PNH’s name comes from a symptom called “hemoglobinuria,” which is reddish or brownish urine. This symptom may occur at any time, but is often worse first thing in the morning. Hemoglobinuria is caused by lots of hemoglobin, a pigment in red blood cells, in your urine.

2. Fatigue

PNH can lead to anemia (low levels of red blood cells), which causes fatigue and tiredness. 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, people with PNH may develop bone marrow failure. This happens when the hematopoietic stem cells within the spongy tissue inside the bones stop working correctly. These stem cells are responsible for making new red blood cells, but they don’t make enough new, healthy cells in people living with PNH.

In addition to fatigue and tiredness, low red blood cell counts can cause:

• Feelings of weakness, dizziness, or confusion
• Dyspnea (shortness of breath)
• Headache
• A fast or irregular heartbeat
• Chest pain
• Feeling less hungry than usual
• Unexpected weight loss
• Pale skin
• Jaundice (a yellow tint to your skin or the whites of your eyes)
• Difficulty 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

Some pain-related symptoms may be the result of anemia. You may develop a headache if your red blood cells can’t carry enough oxygen to your brain. You could also develop chest pain or pressure if oxygen levels in your blood drop because your heart has to work harder to pump blood around your body.

4. Muscle Spasms

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

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

5. Blood Clots

A blood clot occurs when platelets (cell fragments in your blood) clump together and prevent a blood vessel from leaking too much blood after an injury. When an abnormal blood clot forms in a vein, however, it can cause life-threatening health problems.

More than one-third of people with PNH develop blood clots. Possible reasons for this include low levels of nitric oxide or abnormal platelets.

Blood clots may cause different symptoms based on where they are located in the body. Below is a list of symptoms for each place a blood clot may appear:

• Brain (also called a stroke) — Extreme headache, numbness, trouble moving one side of your body, speaking difficulties, or vision problems
• Abdomen — Abdominal pain, swelling, bloating, or feelings of warmth
• Liver — Abdominal pain or jaundice
• Leg or arm (also called deep vein thrombosis) — Swelling, warmth, or pain in one limb
• Lung (also called a pulmonary embolism) — Chest pain, dizziness, anxiety, sweating, breathing difficulties, irregular heartbeats, or coughing up blood
• Skin — Red, warm, swollen, or painful skin

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

While some people with PNH have problems with their blood clotting too easily, others may experience symptoms related to a lack of proper blood clotting. These health issues are caused by thrombocytopenia (low platelet levels).

Thrombocytopenia can lead to bleeding symptoms, including:

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

If you experience ongoing bleeding and can’t get it to stop, get emergency medical care.

7. Infections

Because PNH is partly caused by problems with the stem cells that produce all of 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

PNH sometimes causes kidney problems, although this is rare. There are a few possible reasons for this. The breakdown of red blood cells may cause iron to build up in the kidneys, or blood clots could form in the veins of the kidneys. In some cases, the cause of kidney problems isn’t understood.

Symptoms of kidney damage include urinating less than usual, ankle swelling, inflammation around your eyes, shortness of breath, nausea, and confusion.

9. Inflammation

Very rarely, PNH is accompanied by inflammation that can lead to additional symptoms. These include:

• Hives (an itchy, raised rash)
• Joint or bone pain
• Inflammatory bowel disease (IBD), which often leads to digestive symptoms like abdominal pain, diarrhea, bloody 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 also frequently occurs with related conditions like aplastic anemia and myelodysplastic syndrome (MDS). Some of your symptoms could also be connected to these conditions.

Experiencing these symptoms does not necessarily mean you have PNH. However, if you are having issues like dark urine, fatigue, muscle spasms, blood clots, or bleeding problems, you should talk to your health care provider.

Your doctor, or a specialist such as a hematologist-oncologist, can run tests to determine whether you have a problem with your blood cells and investigate the cause. If your doctor gives you a diagnosis of PNH, they can recommend various therapies. PNH treatment options may eliminate or reduce your symptoms and boost your quality of life and sense of well-being.

Find Your Team

On myPNHteam, the site for people with paroxysmal nocturnal hemoglobinuria and their loved ones, members come together to ask questions, offer advice, and share their stories with others who understand life with PNH.

Have you been diagnosed with PNH? What symptoms of PNH led to your diagnosis? Share your experience in the comments below, or start a conversation on your Activities page.