Hyperviscosity syndrome is a condition in which blood isn’t able to flow freely through your arteries.

In this syndrome, arterial blockages can happen due to too many red blood cells, white blood cells, or proteins in your bloodstream. It can also occur with any abnormally shaped red blood cells, such as with sickle cell anemia.

Hyperviscosity happens in both children and adults. In children, it can affect their growth by reducing blood flow to vital organs, such as the heart, intestines, kidneys and brain.

In adults, it can occur with autoimmune diseases such as rheumatoid arthritis or systemic lupus. It may also develop with blood cancers such as lymphoma and leukemia.

The symptoms associated with this condition include headaches, seizures, and a reddish tone to the skin.

If your infant is unusually sleepy or doesn’t want to feed normally, this is an indication that something is wrong.

Generally, the symptoms associated with this condition are the result of complications that occur when vital organs don’t receive enough oxygen through the blood.

Other symptoms of hyperviscosity syndrome include:

  • abnormal bleeding
  • visual disturbances
  • vertigo
  • chest pain
  • shortness of breath
  • seizure
  • coma
  • difficulty walking

This syndrome is diagnosed in infants when the level of total red blood cells is above 65 percent. This can be caused by numerous conditions that develop during gestation or at the time of birth. These can include:

  • late clamping of the umbilical cord
  • diseases inherited from the parents
  • genetic conditions, such as Down syndrome
  • gestational diabetes

It can also be caused by situations in which there isn’t enough oxygen delivered to the tissues in your child’s body. Twin-to-twin transfusion syndrome, a condition in which twins unequally share blood between them in the uterus, may be another cause.

Hyperviscosity syndrome can also be caused by conditions that affect blood cell production, including:

  • leukemia, a cancer of the blood that results in too many white blood cells
  • polycythemia vera, a cancer of the blood that results in too many red blood cells
  • essential thrombocytosis, a blood condition that occurs when bone marrow produces too many blood platelets
  • myelodysplastic disorders, a group of blood disorders that cause abnormal numbers of certain blood cells, crowding out healthy cells in the bone marrow and often leading to severe anemia

In adults, hyperviscosity syndrome typically causes symptoms when blood viscosity is between 6 and 7, measured relative to saline, but it can be lower. Normal values are usually between 1.6 and 1.9.

During treatment, the goal is to lower viscosity to the level needed to resolve an individual’s symptoms.

This condition often affects infants, but it can also develop in adulthood. The course of this condition depends on its cause:

  • Your baby is at a higher risk of developing this syndrome if you have a family history of it.
  • Also, those who have a history of serious bone marrow conditions are at a greater risk of developing hyperviscosity syndrome.

If your doctor suspects that your infant has this syndrome, they’ll order a blood test to determine the amount of red blood cells in your child’s bloodstream.

Other tests may be necessary to reach a diagnosis. These may include:

Also, your doctor may find that your infant is experiencing things like jaundice, kidney failure, or breathing problems as a result of the syndrome.

If your baby’s doctor determines that your baby has hyperviscosity syndrome, your baby will be monitored for possible complications.

If the condition is severe, your doctor may recommend a partial exchange transfusion. During this procedure, a small amount of blood is slowly removed. At the same time, the amount taken out is replaced with a saline solution. This lowers the total number of red blood cells, making the blood less thick, without losing blood volume.

Your doctor may also recommend more frequent feedings for your baby to improve hydration and reduce blood thickness. If your baby doesn’t respond to feedings, they may need to get fluids intravenously.

In adults, hyperviscosity syndrome is often caused by an underlying condition such as leukemia. The condition needs to be properly treated first to see if this improves the hyperviscosity. In severe situations, plasmapheresis may be used.

If your baby has a mild case of hyperviscosity syndrome and no symptoms, they may not need immediate treatment. There’s a good chance for full recovery, especially if the cause appears to temporary.

If the cause is related to a genetic or inheritable condition, it may require long-term treatment.

Some children who’ve been diagnosed with this syndrome have developmental or neurological problems later on. This is generally the result of a lack of blood flow and oxygen to the brain and other vital organs.

Contact your baby’s doctor if you notice any changes in your infant’s behavior, feeding patterns, or sleeping patterns.

Complications may occur if the condition is more severe or if your baby isn’t responding to treatment. These complications can include:

  • stroke
  • kidney failure
  • decreased motor control
  • loss of movement
  • the death of intestinal tissue
  • recurrent seizures

Be sure to report any symptoms your baby is having to their doctor right away.

In adults, hyperviscosity syndrome is often related to an underlying medical problem.

Proper management of any ongoing illnesses, along with input from a blood specialist, are the best ways to limit complications from this condition.