What Is Paroxysmal Nocturnal Hemoglobinuria (PNH)?

Summary: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare and serious blood disease. It happens when a genetic glitch in your bone marrow causes your body to make defective red blood cells. These abnormal cells are missing a special protein shield. Without this shield, your body’s own immune system mistakes them for invaders and destroys them.

Because this breakdown often happens while you sleep, the destroyed cells release a protein called hemoglobin into your urine, making it look dark or reddish by the morning. This is where the "nocturnal" part of the name comes from. The constant destruction of red blood cells causes extreme tiredness, shortness of breath, and painful muscle spasms. The most dangerous part of PNH is that it can cause severe blood clots, which can block blood flow to major organs like your brain, lungs, or liver.

PNH is not passed down from your parents; the mutation happens randomly during your life. In the past, people with PNH only lived 10 to 20 years after being diagnosed. Today, doctors use special IV medicines that stop the immune system from attacking the red blood cells. Thanks to these new treatments, people with PNH can now expect to live as long as anyone else.

For more details, see Everyday Health at everydayhealth.com/blood-disorders/paroxysmal-nocturnal-hemoglobinuria/guide/ (opens in new tab)