Skip to content

Information and Resources

Paroxysmal Nocturnal Hemoglobinuria (PNH)

Font Size
A
A
A

What Is Paroxysmal Nocturnal Hemoglobinuria?

When you have paroxysmal nocturnal hemoglobinuria (PNH), red blood cells in your body break apart before they should. It happens because the proteins that would normally protect them from your immune system are missing. Your immune system attacks the red blood cells and breaks them down.

You can get this rare blood disease at any age. You aren’t born with it. It happens over time. Although it can be life-threatening, treatments can help you feel better and, in some cases, cure it.

Recommended Related to Mind, Body, Spirit

Jeff Gordon Is Driven to Help Children

Jeff Gordon knows how to win. The numbers don't lie: four NASCAR Sprint Cup Series championships, three Daytona 500 victories, and more than 80 NASCAR wins. But in Gordon's drive to succeed, he is not the only winner. Although he waited until he was 35 to start a family -- his wife, Ingrid, gave birth to daughter Ella Sofia last June -- caring for children has been a priority for quite a long time. In 1992, Ray Evernham, then Gordon's crew chief, came to him with bad news: Evernham's young son,...

Read the Jeff Gordon Is Driven to Help Children article > >

PNH affects everyone differently. Some people have only minor problems, but for others, it's much more severe. The biggest concern is blood clots. About 40% of people with PNH have one at some point.

Causes

PNH comes from your genes, but you don't get it from your parents, and you can't pass it on to your kids.

A change in a gene, called a mutation, causes your bone marrow to make abnormal red blood cells. These cells don't have proteins that shield them from your immune system. So your body attacks them and breaks them down, a process doctors call hemolysis.

Some doctors believe PNH is related to weak bone marrow. People with a certain type of anemia, called aplastic anemia, are more likely to get PNH. The reverse is also true: People with PNH are more likely to get aplastic anemia, though not everyone does. In this condition, your bone marrow stops making new blood cells.

Symptoms

PNH gets its name from one of its more common symptoms. About half of people with PNH pass dark or bright red blood in their urine at night or in the morning. "Paroxysmal" means "sudden," "nocturnal" means "at night," and "hemoglobinuria" means "blood in the urine."

PNH symptoms are caused by:

  • Broken red blood cells
  • Too few red blood cells (which can cause anemia)
  • Blood clots in your veins

You could have many symptoms or just a few. Usually, the more of the faulty blood cells you have in your body, the more the condition will affect you.

1 | 2 | 3 | 4

Hot Topics

WebMD Video: Now Playing

Click here to wach video: Dirty Truth About Hand Washing

Which sex is the worst about washing up? Why is it so important? We’ve got the dirty truth on how and when to wash your hands.

Click here to watch video: Dirty Truth About Hand Washing

Popular Slideshows & Tools on WebMD

feet
Solutions for 19 types.
MS Overview
Recognizing symptoms.
pregnancy test and calendar
Helping you get pregnant.
man rubbing painful knee
A visual guide.
lone star tick
How to identify that bite.
woman standing behind curtains
How it affects you.
brain scan with soda
Tips to avoid complications.
row of colored highlighter pens
Tips for living better.
human lungs
Symptoms, causes, treatments.
woman dreaming
What Do Your Dreams Say About You?
two male hands
Test your knowledge.

Pollen counts, treatment tips, and more.

It's nothing to sneeze at.

Loading ...

Sending your email...

This feature is temporarily unavailable. Please try again later.

Thanks!

Now check your email account on your mobile phone to download your new app.

Women's Health Newsletter

Find out what women really need.