Hyperviscosity syndrome occurs when blood thickens and doesn’t flow freely through blood vessels. Without treatment, this condition could lead to severe complications, including reduced blood flow to your vital organs. With timely treatment, many people recover fully from the syndrome.
Hyperviscosity syndrome occurs when your blood thickens so much that it doesn’t flow freely through your blood vessels. It may happen because you have too many red blood cells, white blood cells or blood proteins. It may also develop if you have irregularly shaped red blood cells.
Hyperviscosity syndrome is a serious condition. Without treatment, it can lead to artery blockages and reduced blood flow to your vital organs. In children, reduced blood flow can affect growth and development.
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People who have a rare condition called Waldenstrom macroglobulinemia are much more likely to develop hyperviscosity syndrome. People with this condition have atypically high levels of a blood protein called macroglobulin. More than 30% of people with Waldenstrom macroglobulinemia develop hyperviscosity syndrome at some point in their lives.
Most often, hyperviscosity syndrome causes:
Less commonly, it may also cause:
Hyperviscosity in a newborn may develop due to:
The most common cause of hyperviscosity syndrome is Waldenstrom macroglobulinemia. Other causes may include:
Healthcare providers typically diagnose hyperviscosity syndrome with blood tests. They may use:
Treatment for hyperviscosity syndrome may vary based on the underlying cause. Hyperviscosity syndrome worsens dehydration, so your provider may prescribe intravenous (IV) hydration. In severe cases, healthcare providers may use:
There’s no way to prevent hyperviscosity syndrome. If you are pregnant, you may take certain steps to lower the risk of your baby doesn't get the condition. You may:
Hyperviscosity syndrome requires prompt treatment. Without treatment, it can lead to life-threatening complications and organ failure.
Babies and adults who receive timely treatment often fully recover from hyperviscosity syndrome. If hyperviscosity syndrome is related to a chronic underlying condition, you may need ongoing treatment to prevent it from developing again.
If you or your child have hyperviscosity syndrome or you think you could, you may also want to ask your healthcare provider:
Hyperviscosity may feel different to different people. Thickened blood leads to poor brain circulation, which can cause headaches, dizziness or confusion. Some people may also feel short of breath or have blurry vision.
Multiple factors can increase blood viscosity. Your blood may thicken if you have irregularly shaped red blood cells. It may also thicken if you have irregularly high levels of any blood component, including red blood cells, white blood cells or blood proteins.
A note from Cleveland Clinic
Hyperviscosity syndrome occurs when your blood thickens and doesn’t flow properly through your body. The syndrome may develop in people who have certain types of blood disorders. Sometimes, it develops in infants who have certain genetic or hereditary disorders. Hyperviscosity syndrome is serious and requires treatment. Many people who receive timely treatment experience a full recovery.
Last reviewed by a Cleveland Clinic medical professional on 07/28/2022.
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